Western Australia in 2012: A warm year

  • Rainfall: Near average for WA; below average for southwest WA
  • Maximum temperature: ninth-highest for WA; second-highest for southwest WA
  • Minimum temperature: Near average for WA; above average for southwest WA

Rainfall in WA during 2012 was near average for the State as a whole, but below average for the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay). Wet months in November and December in the Lower Southwest meant that annual rainfall in the region during 2012 was below average, but not in the lowest 10 per cent of records, after a very dry autumn and winter.

Maximum temperatures were well above average for WA as a whole, with the State recording its ninth-warmest year on record. Very much above average maxima were also observed in the Lower Southwest, which recorded its second-warmest year on record only behind 2010. The Lower Southwest has seen a persistent run of above average monthly temperatures for over three years, with only two below-average months since October 2009. Since comparable annual records commenced in 1910, five of the seven hottest years in the Lower Southwest have occurred since 2006.

Rainfall

Averaged across WA as a whole, rainfall during 2012 was near average. The Southwest Land Division (SWLD) and Eucla recorded below- to very-much-below-average rainfall during 2012, whilst large parts of the Kimberley, east Pilbara, and Interior recorded above- to very-much-above-average rainfall. Wet months were observed for WA as a whole in January (sixth-wettest) and November (eleventh-wettest); while May (fifth-driest), July (third-driest), and August (tenth-driest) were in the lowest 10 per cent of records since 1900, mainly due to low rainfall over southern WA during these months. As a result of the relatively dry months in the middle of the year, WA recorded its third-driest April to October period. The Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) saw below-average rainfall during 2012, largely as a result of registering its eighth-driest autumn, and eighth-driest winter, which included the driest July for the region since comparable records commenced in 1900. The final two months of the year in the Lower Southwest saw very-much-above-average rainfall, with November ranking as eleventh-wettest on record and December sixth-wettest, thus the November–December period was fourth-wettest on record and elevated the annual rainfall total in 2012 above the lowest 10 per cent of records. January to October rainfall in the Lower Southwest was ranked seventh-lowest.

Significant rainfall events during the year were as follows:

  • A monsoonal burst associated with tropical cyclone Iggy crossing the Pilbara coast resulted in very heavy and persistent rainfall in the west Kimberley between 26 and 29 January where Cygnet Bay and Cape Leveque both recorded 4 consecutive days of rainfall over 100 mm, an unprecedented event in WA weather recording history. Both sites recorded January daily rainfall records as a result of this event.
  • March 2012 saw wet conditions through the Kimberley and adjacent parts of the Pilbara and Interior mainly due to a monsoonal burst during the middle of the month. Troughton Island in the north Kimberley recorded a daily total of 260.6 mm on the 14th, which is its third-wettest day in 27 years of observations, and the wettest day recorded in WA during 2012. During the same event, Home Valley observed 244.0 mm in the 24 hours to 9am on the 13th, the highest daily fall on the WA mainland during 2012, while Doongan observed 243.0 mm in the 24 hours to 9am on the 16th. In contrast, a lack of frontal or thunderstorm activity in the southwest of the State saw several sites observe their driest March on record, particularly in the Southwest district. Cape Leeuwin and Cape Naturaliste both recorded their lowest March rainfall in 116 and 109 years of record respectively.
  • A slow-moving trough and low pressure system that moved over the SWLD at the end of May and the start of June brought thunderstorms and moderate to heavy rainfall to southern and eastern parts of the SWLD and adjacent Goldfields. A number of locations in the Southwest and South Coastal districts registered daily rainfall totals exceeding 80 mm during the first two days of June and numerous sites registered their wettest June day on record, whilst some also recorded their wettest day for any month. Peppermint Grove, in the South Coastal district, observed 174.2 mm on the 1st, which is a June record for the site, and the second-highest daily total for any month for the site in 106 years of record, only surpassed by 196.9 mm recorded on 6 May 1921. This was also the second-highest daily total for June on record for the SWLD. Warner Glen in the Southwest district and Kimberley in the South Coastal district recorded 106.4 mm and 88.2 mm respectively in the 24 hours to 9am on the 1st, their wettest days on record, while Tamaru, in the South Coastal district, received a daily total of 116.2 mm on the 2nd, its highest daily total for any month. Several sites in the South Coastal district recorded their highest June total rainfall with the combination of this event and above-average rainfall for the remainder of the month.
  • A series of low pressure systems and cold fronts crossed southwest Western Australia from 7 to 13 June 2012 resulting in significant damage in the region. Two tornadoes were observed with one affecting inner northern Perth suburbs causing extensive localised damage. Cold fronts that brought with them significant wind gusts, some of which were the highest on record for the region, caused an unprecedented number of power outages to mainly western parts of the Southwest Land Division (SWLD), whilst record-high sea levels as a result of significant storm surges caused localised coastal and estuarine inundation. Cape Naturaliste recorded a wind gust of 146 km/h on the 10th as a low pressure system moved close to the Southwest district; this was the highest wind gust recorded in WA during 2012. Refer to Special Climate Statement 40 (http://www.bom.gov.au/climate/current/statements/scs40.pdf) for further information.
  • Record-low rainfall was observed across a large part of southwest WA during July 2012, particularly in western districts, centred on the Lower West. Most sites in the region observed their driest July on record, including Perth, Northam, Goomalling, Narrogin, Wagin, and Collie; all of which have over 100 years of rainfall records. Averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), July 2012 was the driest July since comparable records commenced in 1900, with a mean across the region of just 39 mm. The very low rainfall during July 2012 was the result of persistent high pressure systems over southern WA during the month and a contraction of the usual fronts and westerly winds southwards.
  • A strong cold front moved across western and central WA and into the southeast of the State on 28 November, with a secondary front moving over southwest WA in the afternoon and evening. The passage of an associated rapidly deepening low just off the WA southwest coast brought very strong winds to southern WA, with isolated thunderstorms in the Southwest and South Coastal districts. Numerous sites experienced their highest wind gusts for November in more than ten years, with maximum gusts in excess of 90 km/h reported across southern WA. Rottnest Island observed the strongest wind gust of 117 km/h. Such a strong storm in late spring is a rare occurrence and caused traffic congestion in Perth, with one lane closed on the Kwinana Freeway due to waves on the Swan River over-topping the sea wall, airport delays, and extensive power outages with reports of 50,000 houses affected. Squally conditions continued in southern and western parts of the SWLD on the 29th, and severe gusts were observed near the coast in the Lower West, Southwest, and Southeast Coastal districts, the highest being 117 km/h at Cape Leeuwin.
  • A surface trough interacting with a middle level low near southwest WA produced thunderstorms and very heavy rainfall across parts of southwest WA on 12 and 13 December 2012, with a number of sites observing their wettest December day on record. Daily rainfall in excess of 50 mm was widespread across the Southwest and Lower West districts, with isolated heavier falls of over 100 mm. Slow-moving heavy thunderstorms over the Bunbury to Collie region produced extreme rainfall on the 13th, the highest report being 210.8 mm at Yourdamung Lake (northeast of Collie), which broke the record for the wettest December day on record in the SWLD, and was the fifth-wettest day on record in the SWLD for any month. Extreme rainfall was also observed in Collie, with sites at Collie and Collie East recording 157.2 mm and 135.8 mm respectively. As a result the town of Collie saw significant flash flooding with businesses and residences inundated.
    Refer to Special Climate Statement 42 (http://www.bom.gov.au/climate/current/statements/scs42.pdf) for further information.

Maximum temperature

Averaged across WA as a whole, maximum temperatures during 2012 were very-much-above-average, ranking as the ninth-highest on record. Much of the State recorded above- to very-much-above-average temperatures, with areas of highest on record in the Eucla, southern SWLD, west Gascoyne and northwestern Central West, with a number of sites observing their warmest or equal-warmest year on record. The only region of WA to see a below-average 2012 was the southeast Kimberley. Monthly mean maximum temperatures for WA were below average at the start of the year, but were consistently above average from April to December, and WA recorded its third-warmest April to November period since comparable records commenced in 1950.

The Lower Southwest saw very-much-above-average maximum temperatures, recording its second-warmest year since comparable records commenced in 1910, only behind the record set in 2010. The very-much-above-average year was largely due to an above-average January, a very-much-above-average autumn (fifth-warmest), and consistently above-average maxima from July to October. The Lower Southwest has seen a persistent run of above-average mean monthly maximum temperatures for over three years, with only two months below the average since October 2009. Also of note is that five of the seven hottest years in the Lower Southwest, since comparable annual records commenced in 1910, have occurred since 2006.

Significant maximum temperature events during the year were as follows:

  • Widespread rainfall and overcast conditions brought a number of cooler-than-average days to the east Pilbara during the passage of tropical cyclone Lua in March. Several sites in the region experienced their coolest March day on record on the 17th, with Port Hedland Airport recording a daily maximum temperature of 24.1 °C, which is 12.7 °C below average and 1.7 °C below the previous coolest March day in 64 years of record at the airport. Port Hedland Airport also experienced its coolest March in terms of mean maximum temperature, as did Wittenoom (59 years of record), and Roebourne (54 years of record).
  • Unseasonally hot conditions were observed in the Interior and adjacent Eucla to start April, with Giles observing its equal-hottest April day on record as it registered a maximum temperature of 38.3 °C on the 1st.
  • Consistently warm temperatures over the northwest of WA throughout much of May 2012, associated with the lack of rainfall and clear skies, resulted in Carnarvon Airport, Onslow Airport, Learmonth Airport, and Geraldton Airport all observing their hottest May on record. Of note were hot days from the 2nd to the 4th where temperatures were up to 10 °C above normal in the west Gascoyne and west Pilbara.
  • A high moving south of WA resulted in warm to hot conditions through northwest and central parts of WA from 16 to 21 August. Onslow Airport observed its warmest August temperature in 48 years of record on the 18th, with a maximum of 35.2 °C, while Roebourne Aerodrome equalled its highest August temperature in 11 years of record on both the 20th and 21st with maxima of 35.9 °C. A high over southern Australia brought warm to hot conditions to central and northern WA on 27 and 28 August. Fitzroy Crossing recorded the highest temperature in the State for August 2012 with 38.5 °C on the 27th, only slightly below its 42-year August record of 39.0 °C, whilst Telfer Aerodrome recorded a maximum temperature of 36.0 °C on the 28th, its equal-highest August temperature in 39 years of record. Very-much-above-average August temperatures saw many Pilbara sites record their warmest August on record, including Roebourne, which has 92 years of record.
  • A cool, cloudy, and showery day across western and central parts of WA on 4 September saw unusually low maximum temperatures recorded. Brookton in the Great Southern recorded a maximum temperature of 10.6 °C, its equal-coolest September day in 45 years of record, while Mount Barker in the South Coastal observed the coldest day in WA during September 2012 with a maximum of just 9.8 °C. Another very cold day was observed in the southwest of the State in the wake of a cold front on 27 September, with Karnet in the Lower West recording a maximum temperature of 9.9 °C and most other sites in the area only reaching the low teens.
  • Maximum temperatures during October 2012 were above to very much above average throughout almost all of WA and a number of sites in the SWLD, as well as Emu Creek in the west Pilbara, observed their hottest October on record, including Cape Naturaliste with 109 years of record. A particularly hot day was observed in western WA, away from the west coast, on the 21st as a trough deepened near the west coast and Paynes Find in the Gascoyne observed 39.8 °C, the site's hottest October day in 34 years of record.
  • Hot conditions were observed across central and northwestern WA on 15 November, particularly in the central Pilbara where temperatures reached the mid-forties. Roebourne observed the highest temperature in the State with 46.4 °C. Maxima in excess of 40 °C continued across the Pilbara, inland Kimberley, and Northern Interior on the 16th, particularly in the central Pilbara where temperatures again reached the mid-forties. Roebourne Aerodrome observed the highest temperature on that day with 46.0 °C.
  • A broad trough across inland northern WA resulted in hot conditions in parts of the Pilbara, Gascoyne and Interior on 19 through to 23 December, with temperatures reaching the mid-forties in the inland Pilbara and northwest Gascoyne. Emu Creek recorded a maximum of 47.3 °C on the 23rd, the highest temperature in WA in December 2012.
  • A prolonged spell of hot weather was observed in southwestern WA from Christmas Day through to the end of December, with the hot weather extending across southern WA on the last day of the year. The hot conditions were due to a stagnant weather pattern consisting of a high in the Bight and a trough near the west coast directing generally hot easterly winds over the area with little relief from the seabreeze. Particularly hot conditions were observed on the 30th in the Southwest District, with Cape Naturaliste observing 37.7 °C, its hottest December day in 56 years of record, while Jarrahwood observed 40.5 °C which is an equal record for December. Busselton Aero observed 41.0 °C, its hottest day in 15 years of record, breaking the annual record of 40.2 °C set on 26 January 2012, while Witchcliffe's 40.6 °C equalled their annual record set on 26 January 2012 in 13 years of record.

Minimum temperature

Averaged across WA, minimum temperatures were near average, while for the Lower Southwest, overnight temperatures were above average during 2012. Much of western and southern WA reported above- to very-much-above-average annual mean minimum temperatures, whilst the Kimberley and large parts of the Interior reported below- to very-much-below-average minima.

The year began with relatively low minimum temperatures across much of the State with monthly mean minima averaged across WA below average from January to August, including the fifth-coolest May and the coolest July on record, before state-wide overnight temperatures warmed during the latter part of the year and WA recorded its third-warmest spring since comparable records commenced in 1950. For the Lower Southwest, overnight temperatures were generally above average in most months. January 2012 was the warmest January on record for the Lower Southwest, whilst only May and July saw below-average monthly mean minima.

Eyre in the Eucla district observed its lowest annual minimum temperature in 46 years of record, with an average overnight temperature of 9.3 °C, 0.5 °C below the previous record. This is remarkable given Eyre also recorded its warmest year in terms of the mean maximum temperature; however, 2012 was a relatively dry year at the site suggesting a lack of cloud ensured good conditions for day-time heating, as well as night-time radiative cooling.

Significant minimum temperature events during the year were as follows:

  • Without the cooling effect of sea breezes, the warmest nights of January 2012 for most of western WA coincided with the hottest days, between the 26th and 27th. Jurien Bay in the Central West broke its highest January minimum record on the 26th, whilst Cape Leeuwin in the Southwest recorded two consecutive days with minima over 23 °C (23.5 °C on the 26th, and 23.1 °C on the 27th), both breaking its previous January record of 22.7 °C observed on 23 January 1989, from records commencing in 1907.
  • A hot night due to cloudy conditions and warm northerly winds was observed in western parts of the SWLD on 1 February and throughout much of the SWLD on the 2nd, resulting in Hyden, in the Great Southern, recording its hottest night in 37 years of record with a minimum temperature of 26.5 °C.
  • A strong high moved into the Bight in the wake of a cold front on 23 April, resulting in cool nights across much of the south of the State, with the coldest night of the month in WA observed at Eyre on the 25th when the temperature dropped to –0.1 °C. The cool air pushed northwards over subsequent days, resulting in cool nights over the north of the State to end the month. Wyndham observed its coolest April night in 45 years of record with 15.7 °C on the 30th, breaking its previous record of 15.9 °C set in 2011.
  • Very cold nights were reported in the SWLD, Goldfields, Interior, and adjacent parts of neighbouring districts on 24 and 25 May, resulting in a number of sites in the SWLD observing their coldest May night on record. Another burst of cool air over the north from a strong high over WA in the following days, resulted in relatively low overnight temperatures, particularly in the Kimberley. Broome Airport observed its coolest May temperature in 73 years of record on the 27th, with a minimum of 8.1 °C, and then went lower the following day with a minimum of 7.7 °C. Mount Elizabeth, with 18 years of record, broke its previous May record of 3.7 °C (set on 28 May 1998) on six consecutive days, with minimum temperatures (26th to 31st) of 3.1 °C, 0.5 °C, –0.9 °C, 2.5 °C, 2.8 °C, and 1.7 °C, respectively. The –0.9 °C recorded on the 28th was the first sub-zero minimum temperature ever recorded by the Bureau of Meteorology in the Kimberley.
  • When averaged across the State as a whole, the July 2012 mean minimum temperature ranked as the coldest on record for WA. The cool to cold overnight temperatures observed throughout much of WA during July 2012 were the result of persistent high pressure ridging across the south of the State resulting in generally clear skies and light winds, and an associated lack of rainfall, with frequent subzero minima observed at sites in central and southern WA throughout the month. Well-below-average minima were reported across large parts of WA in the last two days of June and first ten days of July, and Yeelirrie in the Goldfields observed nine consecutive subzero temperatures from 30 June to 8 July, which is the equal-longest spell of subzero nights at the site in 38 years of record, equal with nine subzero nights between 15 and 23 July 1997. WA's coldest nights in 2012 occurred at Yeelirrie on 7 July and Warburton Airfield on 8 July, both with minima of –4.2 °C.

Other notable events

  • Tropical cyclone Heidi formed north of the Pilbara coast on the evening of 10 January and crossed the Pilbara coast as a category two system on the morning of the 12th, approximately 15 km east of Port Hedland. After landfall, Heidi moved on a south-southwest track and weakened into a tropical low over the southern Pilbara. Heidi produced sustained winds of 119 km/h and a maximum gust of 144 km/h at Bedout Island on the 11th, whilst Port Hedland Airport recorded maximum winds of 98 km/h and gusts to 131 km/h early on the 12th. Damage was mainly confined to uprooted trees and minor flooding, with large-scale power outages in South Hedland and Wedgefield. The decaying TC and low brought very heavy rainfall to various locations in the Pilbara and western Kimberley, with unconfirmed reports over 300 mm, and associated flooding.
  • Tropical cyclone Iggy formed to the northwest of Exmouth, off the west Pilbara coast, on the morning of 26 January and remained offshore to the west of WA as it moved southward. Iggy moved in a generally southerly direction as a category two system west of the Gascoyne coast and weakened below tropical cyclone strength on the morning of 2 February before tracking eastward through northern parts of the SWLD on the 3rd, bringing heavy rainfall to locations in the northern Lower West and southern Central West, as well as near-gale-force winds to coastal locations in the Central West. As Iggy moved parallel with the west coast in late January and early February, an associated tidal surge was recorded at most towns from Onslow to Perth, peaking at 80 cm at Geraldton and 70 cm at Fremantle on 2 February.
  • Severe tropical cyclone Lua formed during mid-March off the Pilbara coast before crossing the coast near Pardoo Station on the 17th as a category four system, and weakening as it tracked through central WA. Significant damage was reported from Pardoo Roadhouse and the Yarrie mine site with uprooted trees and damage to buildings. Lua caused moderate to major flooding of the De Grey river system in the east Pilbara, particularly in the vicinity of Tumbinna Pool and Nullagine. Ex-TC Lua moved through the Goldfields, Southeast Coastal, and Eucla between the 19th and 20th, bringing some significant rainfall. Lua was the fifth tropical cyclone in the Western Region for the 2011-12 season, and the second to cross the Pilbara coast.
  • Tropical cyclone Mitchell formed out of a low well to the northwest of the Pilbara coast during the morning of 29 December. Mitchell moved in a generally south-southwest direction, remaining off the coast and weakening below cyclone strength during the morning of the 30th. Mitchell was a category 1 system and the first tropical cyclone for the Western Region in the 2012/13 season.

Further information

Media
(03) 9669 4057
Enquiries

Extremes in 2012
Hottest day 47.3 °C at Emu Creek Station on 23 Dec
Warmest days on average 35.7 °C at Fitzroy Crossing Aero
Coolest days on average 20.8 °C at Albany
Coldest day 9.8 °C at Mount Barker on 4 Sep
Coldest night -4.2 °C at Yeelirrie on 7 Jul
-4.2 °C at Warburton Airfield on 8 Jul
Coolest nights on average 8.5 °C at Collie East
Warmest nights on average 23.7 °C at Varanus Island
21.8 °C at Wyndham
Warmest night 32.7 °C at Emu Creek Station on 24 Dec
Wettest overall 1723.2 at Doongan
Wettest day 260.6 mm at Troughton Island on 14 Mar
244.0 mm at Home Valley on 13 Mar
Highest wind gust 146 km/h at Cape Naturaliste on 10 Jun

Maps
ObservedAnomalyDecile rank
Total
rainfall
Map of Rainfall totals Map of Percentage of normal rainfall Map of Rainfall deciles
Mean
daily
maximum
temperatures
Map of Mean maximum temperature Map of Anomaly in mean maximum temperature Map of Decile rank of mean maximum temperature
Mean
daily
minimum
temperatures
Map of Mean minimum temperature Map of Anomaly in mean minimum temperature Map of Decile rank of mean minimum temperature

Record highest daily rainfall
Highest daily rainfall
in 2012 (mm)
Previous annual
wettest
Years of
record
Collie 157.2 on 13 Dec 118.4 on 21 Jan 1982 109
Warner Glen 106.4 on 1 Jun 104.4 on 14 Jan 1954 63
Tamaru 116.2 on 2 Jun 112.7 on 2 Aug 1992 47
Kimberley 88.2 on 1 Jun 84.6 on 1 Apr 1983 44
Alexandra Bridge 107.2 on 1 Jun 82.0 on 27 May 2010 42



Record highest annual mean daily maximum temperature
Mean daily maximum
temperature
for 2012 (°C)
Previous annual
warmest
Years of
record
Annual
average
Narrogin 23.6 = 23.6 in 2010 81 22.4
Manjimup 22.1 22.0 in 2011 71 20.3
Carnarvon Airport 28.9 = 28.9 in 1988 64 27.2
Eyre 24.8 24.3 in 2007 46 22.8
Esperance 22.7 = 22.7 in 1983 42 21.8
Ongerup 23.0 22.9 in 1972 41 21.7



Record highest daily minimum temperature
Highest daily minimum
temperature
in 2012 (°C)
Previous annual
warmest
Years of
record
Annual
average
Hyden 26.5 on 2 Feb 26.3 on 5 Jan 1977 42 9.9



Record lowest annual mean daily minimum temperature
Mean daily minimum
temperature
for 2012 (°C)
Previous annual
coolest
Years of
record
Annual
average
Eyre 9.4 9.8 in 2006 46 10.8



Month by month
January
  • Rainfall: sixth-wettest on record for WA
  • Maximum temperature: third-coolest on record for WA; above average in southwest WA
  • Minimum temperature: below average for WA; warmest on record in southwest WA

An active monsoon across the north of WA, the passage of tropical cyclone Heidi across the Pilbara, and the influence of tropical cyclone Iggy off the west Pilbara coast, resulted in above- to very-much-above-average rainfall for much of the State during January 2012. A number of sites in the west Kimberley, Pilbara, and north Gascoyne registered their wettest January on record. Very heavy and persistent rainfall was observed in the west Kimberley between the 26th and 29th where Cygnet Bay and Cape Leveque both recorded 4 consecutive days of rainfall over 100 mm, an unprecedented event in WA weather recording history. Both sites recorded January daily rainfall records as a result of this event.

Maximum temperatures in WA during January 2012 were much cooler than average over large parts of central and northern WA, but above average near the west coast. When averaged over the State, January 2012 was the third-coolest January on record. Minimum temperatures followed a similar pattern, with cooler-than-average temperatures in central and northern parts, and warmer-than-average nights in western and southern areas. The Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) experienced its hottest January in terms of overnight temperatures.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
Rainfall rank Maximum temperature rank Minimum temperature rank
February
  • Rainfall: near average; above average in southwest WA
  • Maximum temperature: near average
  • Minimum temperature: below average for WA; above average in southwest WA

Rainfall during February 2012 was near average for much of WA. Below-average rainfall was observed in the north of the State due to a break in the wet season, whilst the eastern Eucla also saw below-average rainfall. Above-average rainfall was observed in the southwest Gascoyne and parts of the Southwest Land Division (SWLD), particularly near the west coast, mainly due to the passage of ex-tropical cyclone Iggy early in the month. Above-average rainfall was also reported in the central Interior.

Maximum temperatures were near normal across much of the State during February 2012. Above average daytime temperatures were evident in the Kimberley, coastal Eucla and near the southwest Capes, while below average maxima were confined to the central Interior. Minimum temperatures were below to very much average over much of eastern WA, contrasting with above average overnight minima in the SWLD, and in patches of the west Gascoyne, west Pilbara and north Kimberley.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
March
  • Rainfall: above average for WA; fifth-driest March for southwest WA
  • Maximum temperature: below average for WA; sixth-warmest March for southwest WA
  • Minimum temperature: below average for WA, near average for southwest WA

March 2012 saw wet conditions through the Kimberley and adjacent parts of the Pilbara and Interior mainly due to a monsoonal burst during the middle of the month. Above average rainfall was also observed in parts of central and southeastern WA, mostly as a result of ex-tropical cyclone Lua moving through the region. In contrast, below-average rainfall was observed in western and southwestern parts, with a number of sites observing their lowest March rainfall total on record, although March rainfall is typically low. The Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) experienced its fifth-driest March since comparable records commenced in 1900; whilst WA as a whole saw above-average rainfall.

Much of northern, central and eastern WA saw below to very- much-below-average maximum temperatures in March 2012. Relatively cool days were evident through central WA during the middle part of the month due to the passage of Lua, and Port Hedland Airport observed its coolest March day, and month, on record. In contrast, very hot conditions were evident in western parts of the Gascoyne and Southwest Land Division (SWLD) during the first half of the month, with numerous locations observing multiple days over 40 °C. The Lower Southwest observed its sixth warmest March on record, primarily due to the hot start to the month, though WA as a whole recorded a below-average month for maximum temperatures. The pattern of minimum temperatures was similar to maximum temperatures, with mostly cooler-than-average conditions in northern, central and eastern parts, and warm conditions near the west and south coasts. Averaged across WA as a whole, March 2012 was below average in terms of the overnight temperature, whilst the Lower Southwest was near average.

Severe tropical cyclone Lua formed during mid-March off the Pilbara coast before crossing the coast near Pardoo Station on the 17th and weakening as it tracked through central WA. Lua was the fifth tropical cyclone in the Western Region for the 2011-12 season, and the second to cross the Pilbara coast.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
April
  • Rainfall: below average
  • Maximum temperature: near average for WA, above average for southwest WA
  • Minimum temperature: below average for WA, above average for southwest WA

Rainfall during April 2012 was below average in much of the southern half of WA apart from much of the Lower West, which recorded near-average to above-average April rainfall as a result of a rainfall event during the last few days of the month. In the north of the State, rainfall was mostly near-average, although parts of the east Kimberley experienced some heavy rainfall towards the end of the month. When averaged across the State, April 2012 rainfall was below average. Rainfall across the Southwest Land Division (SWLD) as a whole was also below average; however, the Lower Southwest (southwest a line from Jurien Bay to Bremer Bay) recorded near-average rainfall.

Much of southern and western WA, as well as the Interior, saw above-average maximum temperatures in April 2012, with Eyre in the Eucla observing its warmest April on record, largely as a result of a very warm first half of the month. Below-average maximum temperatures were confined to the east Kimberley and coastal parts of the east Pilbara and far west Kimberley. Overnight temperatures were close to average for large parts of WA during April 2012, apart from areas of above-average maxima in much of the SWLD, eastern Eucla, and southeast and central Interior, and areas of below-average minima in the northern Goldfields, east Gascoyne, southeast Pilbara and much of the Kimberley.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
May
  • Rainfall: fifth-lowest on record for WA
  • Maximum temperature: above average
  • Minimum temperature: fifth-lowest on record for WA; near average for southwest WA

Rainfall during May 2012 was below average throughout much of WA, with areas of very-much-below-average rainfall scattered throughout the State. When averaged across the State as a whole, May 2012 rainfall was very much below average and ranked as fifth-lowest on record. The Lower Southwest (southwest a line from Jurien Bay to Bremer Bay) also observed below average rainfall.

Most of WA, apart from the northeast of the State, observed above-average day-time temperatures during May 2012, with consistently warm conditions across the month in the northwest resulting in some stations observing their warmest May on record. Overnight temperatures were below to very much below average in the Kimberley, east Pilbara, and northern and eastern Interior, with near-average conditions in the remainder of WA during May.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
June
  • Rainfall: near average
  • Maximum temperature: near average
  • Minimum temperature: near average for WA; above average for southwest WA

Rainfall during June 2012 was near average for much of Western Australia. Above- to very-much-above-average rainfall was observed in isolated parts of western, central, and southern WA, and a number of sites in the South Coastal district observed their wettest June on record, partly due to a significant rainfall event early in the month. In what is typically a dry time of year in the north of WA, areas of above-average rainfall were observed in small parts of the Pilbara, particularly around Karratha, while large areas of below-average rainfall were observed in the Kimberley and central Interior.

Above-average maximum temperatures were observed in much of western, central and southwestern WA during June, with below-average daytime temperatures only observed in the east Kimberley. Averaged across the State as a whole, the mean maximum temperature for WA during June was close to average. Minimum temperatures were below average in northern and eastern parts of WA, while western parts reported above- to very-much-above-average mean minima. Averaged across the State as a whole, the June mean minimum temperature was near average; however the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) observed above-average overnight temperatures.

A series of low pressure systems and cold fronts crossed southwest WA from 7 to 13 June resulting in significant damage in the region. Two tornadoes were observed with one affecting inner northern Perth suburbs causing extensive localised damage. Significant wind gusts that were some of the highest on record for the region caused an unprecedented number of power outages to mainly western parts of the Southwest Land Division (SWLD), and unusually high sea levels as a result of storm surges caused localised coastal and estuarine inundation. Refer to http://www.bom.gov.au/climate/current/statements/scs40.pdf for further information.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
July
  • Rainfall: third-driest on record for WA; driest on record for southwest WA
  • Maximum temperature: near average for WA; seventh-warmest on record for southwest WA
  • Minimum temperature: lowest on record for WA; below average for southwest WA

Record-low rainfall was observed across a large part of southwest WA during July 2012 particularly in western districts, centred on the Lower West. A large number of sites observed their driest July on record, many with over 100 years of rainfall records. Averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), July 2012 was the driest July on record whilst for the State as a whole it was the third-driest July on record (comparable records commenced in 1900). The very low rainfall during July 2012 was the result of persistent high pressure systems over southern WA during the month and a contraction of the usual fronts and westerly winds southwards.

Most of WA saw below- to very-much-below-average mean minimum temperatures during July 2012, with areas of lowest on record in the central eastern and southeastern Interior, and in central and eastern parts of the Southwest Land Division (SWLD). As a result WA observed its coldest July on record (comparable records commenced in 1950). Above- to very-much-above-average maximum temperatures were observed over much of western WA during July 2012, resulting in the Lower Southwest observing its seventh-warmest July on record.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
August
  • Rainfall: tenth driest on record for WA
  • Maximum temperature: second-highest on record for WA
  • Minimum temperature: near average

Rainfall during August 2012 was below to very much below average throughout most of WA, ranking as tenth-lowest on record for the State as a whole. Rainfall was particularly low in southeastern WA where several sites in the Eucla recorded less than 3 mm for the month and Eyre observed its lowest August rainfall in 83 years of record. The Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) observed below average rainfall again during August 2012, following its driest July on record, and has observed its fifth-driest January to August period since comparable records commenced in 1900.

Maximum temperatures during August were above to very much above average throughout WA, with areas of highest on record throughout most of the Pilbara and parts of the west Kimberley where a number of sites registered their warmest August on record. When averaged across the State as a whole, the mean maximum temperature during August 2012 ranked as second-highest on record for WA, continuing a run since April of five consecutive above average months for the State. Mean maximum temperatures were also above-average in the Lower Southwest, with above average mean maxima for almost all months, except February, resulting in the third-warmest January to August period for this region since comparable temperature records commenced in 1950.

Overnight temperatures were near average across WA as a whole in August 2012, with below- to very- much-below-average minimum temperatures observed across the Kimberley, adjacent Interior and coastal east Pilbara contrasting with above- to very-much-above-average minimum temperatures in large parts of central, western and southern WA.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
September
  • Rainfall: near average; above average for southwest WA.
  • Maximum temperature: fourth-highest for WA; above average for southwest WA
  • Minimum temperature: above average for WA; near average for southwest WA

When averaged across WA as a whole, rainfall during September 2012 was near-average. Western parts of the Southwest Land Division (SWLD) saw near-average to above-average rainfall during September 2012, with small areas of very-much-above-average rainfall. Walpole in the South Coastal and sites in the western Great Southern observed their wettest September on record. In contrast, below- to very-much-below-average rainfall was observed in much of the central and southern Interior, and Eucla, as rainfall totals were generally low outside the SWLD.

Maximum temperatures during September 2012 were above to very much above average throughout almost all of WA, with the State recording its fourth-highest mean maximum temperature since comparable temperature records commenced in 1950. Areas of highest on record were observed in southeastern and northern parts of the State. Eucla and Eyre, both in the Eucla district, observed their equal warmest and warmest September on record respectively. Minimum temperatures were above average for WA as a whole, with below- to very-much-below-average minimum temperatures in the northern Kimberley contrasting with above- to very-much-above-average overnight temperatures for much of the remainder of the State.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature

October

  • Rainfall: near average for WA; eighth-driest for southwest WA
  • Maximum temperature: seventh-highest for WA; second-highest for southwest WA
  • Minimum temperature: seventh-highest for WA; above average for southwest WA

Rainfall in the southern half of WA was mostly below to very much below average during October 2012, with sites in the South and Southeast Coastal, and Great Southern recording their lowest October rainfall. Averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), October 2012 rainfall ranked as eighth-lowest since comparable records commenced in 1900; whilst the SWLD ranked as fifth-lowest. The northern half of the State generally saw above- to very-much-above-average rainfall, with Paraburdoo in the Pilbara registering its wettest October in 37 years of records, albeit with a total of 32.8 mm for the month. As a result of the contrasting north and south, October rainfall was near-average for WA as a whole.

Maximum temperatures during October 2012 were above- to very-much-above-average throughout almost all of WA apart from the east Kimberley and northeastern Interior, which saw near-average day-time temperatures. A number of sites in the Southwest Land Division observed their warmest October on record, including Cape Naturaliste with 109 years of record; whilst Emu Creek Station in the west Pilbara also recorded its highest October mean maximum temperature. When averaged across the State, the mean maximum temperature for October 2012 ranked as seventh-highest on record and the Lower Southwest ranked as second-highest on record. Much of the Kimberley and northeastern Interior saw below- to very-much-below-average overnight minima during October 2012; however, most of the remainder of WA recorded above- to very-much-above-average minimum temperatures, with sites in eastern parts of the SWLD and in the Goldfields reporting their highest October mean minimum temperature on record.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature

November

  • Rainfall: eleventh-wettest for WA and southwest WA
  • Maximum temperature: above average for WA; near average for southwest WA
  • Minimum temperature: above average for WA; near average in southwest WA

Rainfall during November 2012 was above- to very-much-above-average through most of the Southwest Land Division (SWLD), particularly in northern and eastern parts where numerous sites, many with over 100 years of record, observed their wettest November on record. Rainfall was also above- to very-much-above-average in the west and south Gascoyne, the Goldfields, east Pilbara, Southern Interior, western Eucla, and parts of the Kimberley, with some sites in the Kimberley observing record daily and monthly totals due to thunderstorm activity. The only part of WA to experience significant below-average rainfall was in eastern parts of the Northern Interior, and northeastern Southern Interior.

Averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), November rainfall was very much above average and in the highest 10 per cent of observations, ranking as eleventh-highest on record. For the SWLD, area averaged rainfall was third-highest on record, while averaged across the State as a whole, November 2012 rainfall ranked as eleventh-highest on record. Comparable area-averaged records commenced in 1900.

Maximum temperatures during November 2012 were above- to very-much-above-average in the west Kimberley, Interior, central Pilbara, northeast Gascoyne, Eucla, and South and Southeast Coastal districts, while northeastern parts of the SWLD and small areas in the west Pilbara saw below-average daytime maxima. The remainder of the State was generally within 1 °C of the average. When averaged across the State as a whole, the mean maximum temperature during November 2012 was in the above-average range, continuing a run of eight consecutive above-average months since April. Mean maximum temperatures were close to, but slightly above, average in the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay).

Minimum temperatures were above- to very-much-above-average across an area stretching from the east Pilbara and west Kimberley into the Interior and Eucla. Above-average minima were also experienced in the west Pilbara and southeastern SWLD, while the remainder of the State was generally close to normal. When averaged across the State as a whole, the mean minimum temperature during November 2012 was above average, while the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) saw close to, but slightly above average, overnight temperatures.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
December
  • Rainfall: above-average for WA; sixth-wettest on record for southwest WA
  • Maximum temperature: above-average for WA; sixth-highest on record for southwest WA
  • Minimum temperature: third-highest on record for WA; fourth-highest on record for southwest WA

Averaged across the state as a whole, rainfall during December 2012 was above-average, while for the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) rainfall ranked as the sixth wettest December since comparable records commenced in 1900. For the wider SWLD, December 2012 rainfall was above-average. Significant rainfall was observed in

A surface trough interacting with a middle level low near southwest WA produced thunderstorms and very heavy rainfall across parts of southwest WA on 12 and 13 December 2012, with a number of sites observing their wettest December day on record. Daily rainfall in excess of 50 mm was widespread across the Southwest and Lower West districts, with isolated heavier falls of over 100 mm. Slow-moving heavy thunderstorms over the Bunbury to Collie region produced extreme rainfall on the 13th, the highest report being 210.8 mm at Yourdamung Lake (northeast of Collie), which broke the record for the wettest December day on record in the SWLD, and was the fifth-wettest day on record in the SWLD for any month. Extreme rainfall was also observed in Collie, with sites at Collie and Collie East recording 157.2 mm and 135.8 mm respectively. As a result the town of Collie saw significant flash flooding with businesses and residences inundated.
Refer to Special Climate Statement 42 (http://www.bom.gov.au/climate/current/statements/scs42.pdf) for further information.

When averaged across the state as a whole, the mean maximum temperature for December 2012 was above-average, continuing the run since April of consecutive mean maxima above the average. After a reasonably cool first half of December 2012, very hot conditions in the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) towards the end of the month resulted in the region observing its fifth hottest December since comparable records commenced in 1950.

Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
Rainfall rank Maximum temperature rank Minimum temperature rank


Summary statistics for 2012
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean
for
2012
Diff
from
average
Highest
for
2012
Mean
for
2012
Diff
from
average
Lowest
for
2012
Total
for
2012
Average
annual
total
Rank
of
2012
Fraction
of annual
average
North Kimberley (district 01)
Kalumburu 33.7 -0.5 39.2 13 Sep 19.5 -0.8 7.6 29 May        
Wyndham 34.9 -0.7 42.9 7 Dec 21.8 -1.4 10.5 26 Jun 947.1 817.3 high 116%
Wyndham Aero 35.5 -0.2 43.8 7 Dec 21.3 -0.9 8.9 12 Aug 714.8 834.9 average 86%
East Kimberley (district 02)
Argyle Aerodrome 34.6 0.0 44.0 7 Dec 21.1 -1.0 9.1 25 Jun 679.0 764.2 average 89%
Halls Creek Airport 33.0 -0.6 43.5 8 Dec 19.1 -0.9 7.1 7 Jul 587.0 566.4 average 104%
Kununurra Aero 34.9 +0.1 43.2 6 Dec 19.5 -1.8 6.7 7 Jul 959.4 828.2 high 116%
Warmun 34.5 -0.5 43.1 8 Nov         793.3 723.1 average 110%
West Kimberley (district 03)
Bidyadanga 33.7 +0.4 45.3 9 Dec     10.2 27 May 1021.8 514.3 v high 199%
Broome Airport 32.7 +0.5 43.0 9 Dec 20.7 -0.5 7.4 3 Aug 686.4 607.3 average 113%
Curtin Aero 35.5 0.0 43.4 8 Dec 19.8 -1.2 6.2 8 Jul 1141.0 863.7 high 132%
Derby Aero 34.3 -0.2 43.3 8 Dec 20.1 -1.4 6.1 27 Jun 899.8 690.8 high 130%
Fitzroy Crossing Aero 35.7 -0.2 45.0 8 Dec 18.8 -1.3 3.9 4 Jul 772.0 725.1 high 106%
West Roebuck 34.3 +0.4 45.0 9 Dec 19.1 -0.8 3.6 25 Jun 783.8 853.1 average 92%
De Grey (district 04)
Karratha Aero 32.5 +0.2 43.6 15 Nov 20.4 -0.4 7.3 7 Jul 273.8 295.6 average 93%
Marble Bar 35.1 -0.3 45.3 24 Dec 19.6 -0.8 5.4 9 Jul 404.8 352.9 average 115%
Port Hedland Airport 33.4 +0.2 42.7 10 Dec 19.3 -0.1 5.8 9 Jul 457.2 315.3 high 145%
Roebourne 34.7 +0.7 46.4 15 Nov 20.3 -0.2 6.4 8 Jul 344.4 312.3 average 110%
Roebourne Aero 34.4 -0.3 46.0 16 Nov 19.1 -0.7 4.5 8 Jul 426.4 272.2 high 157%
Fortescue (district 05)
Barrow Island Airport 29.5 +0.4 38.8 24 Dec 22.4 +0.2 11.8 15 Jul 235.8 291.2 average 81%
Learmonth Airport 32.6 +0.8 46.6 23 Dec 17.9 +0.2 4.0 6 Jul 163.0 251.9 low 65%
Mardie 34.1 +0.2 44.8 14 Feb 19.2 +0.5 5.9 9 Jul 133.6 274.6 low 49%
Onslow Airport 32.9 +1.0 44.8 13 Feb 20.0 +1.0 7.5 16 Jul 128.0 320.7 low 40%
Wittenoom 33.1 +0.2 44.5 24 Dec 19.5 -0.2 4.0 15 Jul 604.0 461.7 high 131%
West Gascoyne (district 06)
Carnarvon Airport 28.9 +1.7 43.7 28 Jan 17.3 +0.1 3.3 6 Jul 173.0 230.5 average 75%
Emu Creek Station         18.6 +0.4 5.6 7 Jul 303.6 299.2 average 101%
Shark Bay Airport 29.8 +0.9 44.8 24 Jan 16.7 +0.4 4.7 4 Jul 181.0 209.5 average 86%
East Gascoyne (district 07)
Newman Aero 31.7 -0.2 44.4 24 Dec         453.2 325.9 high 139%
Paraburdoo Aero 33.4 0.0 44.6 23 Dec 17.9 -0.1 1.8 6 Jul 453.0 323.1 high 140%
Murchison (district 07A)
Meekatharra Airport 29.4 +0.5 42.8 24 Dec 15.8 -0.1 1.8 13 Jul 293.0 239.0 average 123%
Mount Magnet Aero 29.0 +0.6 44.1 21 Dec 15.2 +0.2 1.9 22 Jun 220.0 261.3 average 84%
North Coast (district 08)
Geraldton Airport 27.5   43.9 31 Dec 14.2   1.8 25 Jul 314.4
Kalbarri 29.1 +1.5 44.8 27 Jan 15.4 +0.9 1.4 6 Jul 267.2 350.4 low 76%
Morawa Airport 28.5 +0.4 43.7 26 Dec 13.1 +0.4 1.3 25 Jul 296.0 289.6 average 102%
Mullewa 29.0 +1.1 44.5 26 Dec 14.3 +1.2 2.4 13 Jul 221.8 334.4 low 66%
North Island 25.8 +1.2 37.4 6 Mar 18.9 +0.4 7.7 16 Jul 285.8 288.7 average 99%
Wongan Hills 26.6 +0.9 42.2 26 Dec 12.4 +0.5 0.0 25 Jul 344.9 388.4 average 89%
Central Coast (district 09)
Badgingarra Research Stn 26.1 +0.2 41.8 26 Dec 12.6 +0.7 1.8 25 Jul 510.6 551.6 average 93%
Bickley 22.7 +0.2 38.6 31 Dec 11.7 +0.6 2.9 9 Jul 1063.6 1079.5 average 99%
Champion Lakes 24.8   40.8 31 Dec 14.1   2.7 25 Jul 711.0
Garden Island HSF 23.3 +0.7 40.2 25 Jan 15.2 +0.4 5.6 13 Jul 590.6 605.8 average 97%
Gingin Aero 26.0 +0.6 41.5 31 Dec 11.6 +0.7 -2.7 25 Jul 636.6 631.7 average 101%
Jandakot Aero 25.3 +0.8 41.5 26 Jan 11.8 +0.5 -1.6 25 Jul 684.4 827.4 low 83%
Jurien Bay 26.2 +1.4 43.2 24 Jan 13.6 +0.6 0.5 25 Jul 520.8 561.9 average 93%
Karnet 22.9 +0.4 39.0 28 Jan 10.9 +0.3 -0.6 28 Sep 1121.9 1170.1 average 96%
Lancelin 25.8 +1.7 42.7 25 Jan         479.8 600.2 low 80%
Pearce RAAF 26.2 +1.1 42.7 31 Dec 12.5 +0.3 -0.8 25 Jul 544.5 655.5 low 83%
Perth Airport 25.7 +1.3 42.2 31 Dec 12.6 +0.5 -0.7 25 Jul 647.4 773.2 low 84%
Perth Metro* 25.7 +1.1 42.1 31 Dec 13.2 +0.5 0.4 25 Jul 608.2 850.0 low 72%
Rottnest Island 23.2 +1.1 39.5 25 Jan 16.3 +0.7 8.9 28 Sep 493.6 682.7 low 72%
Swanbourne 25.3 +1.3 43.1 26 Jan 14.3 +0.5 3.9 25 Jul 694.8 724.1 average 96%
South Coast (district 09A)
Albany 20.8 +1.3 37.3 6 Mar 13.0 +1.3 4.5 10 Aug 913.5 931.3 average 98%
Bunbury 23.6 +0.6 40.4 25 Jan 11.4 +0.4 -0.1 25 May 765.6 729.1 average 105%
Busselton Aero 23.6 +0.6 41.0 30 Dec 10.4 +0.2 0.4 25 May 569.8 689.8 low 83%
Cape Leeuwin 21.1 +1.4 37.9 6 Mar 15.2 +1.1 7.1 9 Jul 770.0 967.4 low 80%
Cape Naturaliste 22.6 +2.0 37.7 30 Dec 13.7 +1.0 5.1 24 Jul 619.6 808.9 low 77%
Collie East 23.5   39.4 30 Dec 8.5   -3.1 25 May 776.8 730.5 average 106%
Donnybrook 24.2 +1.1 40.5 27 Jan 10.9 +1.2 0.0 9 Jul 861.6 975.5 low 88%
Dwellingup 23.1 +1.3 39.7 26 Jan 10.1 +0.6 -1.2 25 May 1119.8 1243.1 low 90%
Esperance 22.7 +0.9 42.4 23 Feb 12.5 +0.5 4.7 20 Jul 590.0 616.0 average 96%
Esperance Aero 22.9 +0.9 41.6 23 Feb 11.4 +0.1 3.2 20 Jul 549.8 565.2 average 97%
Harvey 24.2 +0.6 40.0 30 Dec         822.2 851.7 low 97%
Hopetoun North 22.4 +0.2 43.5 23 Feb 11.2 -0.3 0.9 11 Oct 458.6 498.7 low 92%
Jarrahwood 23.8 +1.3 40.7 26 Jan 8.7 +0.1 -3.0 24 May 809.4 924.7 low 88%
Mandurah 23.9 +0.8 41.1 25 Jan 15.2 +0.5 5.8 19 Jul 796.2 673.1 high 118%
Manjimup 22.1 +1.8 40.6 30 Dec 10.4 +0.7 1.8 9 Jul 683.2 1002.0 v low 68%
North Walpole 21.0   38.1 6 Mar 11.8   3.8 10 Aug
Pemberton 21.9 +1.6 39.6 31 Dec         1000.1 1188.6 low 84%
Rocky Gully 21.9 +1.1 40.9 30 Dec 9.8 +0.2 0.3 9 Jul 644.6 696.5 average 93%
Windy Harbour 20.9 +0.7 39.4 6 Mar         1032.2 1063.9 average 97%
Witchcliffe 22.4 +1.1 40.6 30 Dec 10.9 +0.3 0.6 24 May 1087.2 958.5 high 113%
North Central (district 10)
Bencubbin 26.1 +0.7 42.4 26 Dec 12.4 +0.8 0.1 19 Jul 339.4 316.2 average 107%
Cunderdin Airfield 26.7 +0.9 43.1 28 Jan 10.6 +0.2 -2.9 19 Jul 225.2 295.1 low 76%
Merredin 26.3 +1.3 42.5 26 Dec 11.9 +0.5 -2.5 25 Jul 315.7 325.9 average 97%
Northam 26.4 +1.1 42.2 26 Dec         329.9 428.1 low 77%
York 26.1 +0.6 42.3 28 Jan         345.7 378.4 low 91%
South Central (district 10A)
Beverley         10.4 +0.2 -2.6 19 Jul 323.4 418.7 low 77%
Brookton 25.0 +0.8 41.4 31 Dec 10.2 +0.5 -2.1 19 Jul 300.1 450.5 v low 67%
Corrigin 25.0 +1.3 41.6 31 Dec 10.2 +0.2 -2.3 19 Jul 237.8 371.9 v low 64%
Hyden 26.1 +1.1 42.0 31 Dec 10.3 +0.4 -3.5 19 Jul 280.0 339.5 low 82%
Katanning 23.1 +0.7 40.5 30 Dec 9.7 +0.2 -0.1 23 Sep 481.0 456.1 average 105%
Lake Grace 24.1 +0.7 40.6 31 Dec 10.7 +0.5 -1.1 18 Jul 283.0 331.2 low 85%
Narembeen 26.2 +1.0 42.0 28 Jan 11.2 +0.6 -1.6 25 Jul 322.0 332.3 average 97%
Narrogin 23.6 +1.2 40.5 30 Dec 10.1 +0.7 -1.2 9 Jul 350.2 494.9 v low 71%
Newdegate Research Station 24.3 +1.0 41.3 28 Jan 8.7 0.0 -2.6 20 Jul
Ongerup 23.0 +1.3 40.7 28 Jan 10.1 +0.3 -0.9 25 May 341.9 385.5 low 89%
Pingelly 24.5 +1.2 40.6 31 Dec 10.7 +0.3 -1.0 19 Jul 330.6 445.9 low 74%
Ravensthorpe 23.7 +1.0 41.2 23 Feb 11.1 +0.7 1.3 23 Sep 333.2 424.2 low 79%
Wagin 23.8 +0.9 40.7 30 Dec 9.8 +0.1 -1.0 9 Jul 334.8 434.1 low 77%
Wandering 24.0 +0.3 41.1 30 Dec 8.8 +0.4 -3.4 25 May 513.2 507.5 average 101%
Eucla (district 11)
Balladonia 25.5 +0.9 42.2 31 Dec 10.2 +0.4 -1.4 14 Aug 255.4 262.5 average 97%
Eucla 24.2 +1.4 43.3 19 Nov 12.1 -0.1 0.9 15 Jun 230.2 272.1 average 85%
Eyre 24.8 +2.0 45.4 22 Dec 9.4 -1.4 -4.0 15 Jun 257.7 309.8 low 83%
Forrest 27.3 +1.2 43.6 22 Dec 10.3 -0.6 -1.9 1 Jul 88.4 232.7 v low 38%
Red Rocks Point 23.2   43.9 24 Feb 12.9   1.3 15 Jun 202.6
South East (district 12)
Bulga Downs 28.9   43.0 17 Feb 13.2   -1.3 7 Jul 270.9 234.7 average 115%
Kalgoorlie-Boulder Airport 25.8 +0.5 42.6 17 Feb 12.3 +0.6 -1.1 14 Aug 241.0 264.2 average 91%
Laverton Aero 27.7 +0.9 43.8 22 Dec 13.9 0.0 -1.0 14 Jul 261.0 292.9 average 89%
Leonora 27.9 0.0 43.9 16 Feb 13.7 -0.2 0.1 16 Jul 282.4 236.5 average 119%
Munglinup West 23.8   42.6 23 Feb 10.7   2.6 28 Sep
Norseman Aero 25.3 +0.2 41.6 31 Dec 9.9 +0.1 -3.6 14 Aug 275.6 291.5 average 95%
Salmon Gums Res.Stn. 24.5 +1.1 41.3 31 Dec 9.1 +0.1 -3.3 9 Aug 325.2 353.2 average 92%
Southern Cross Airfield 26.2 +0.4 43.8 21 Dec 10.8 +0.6 -2.9 25 Jul 230.8 308.6 low 75%
North East (district 13)
Giles Meteorological Office 29.8 +0.5 43.8 24 Dec 15.0 -0.9 0.0 23 Jun 228.4 287.2 average 80%
Telfer Aero 34.3 +0.2 45.5 24 Dec 19.3 -0.1 4.4 4 Jul 251.0 363.8 average 69%
Warburton Airfield 30.2 +0.5 44.6 23 Dec 14.4 -0.3 -4.2 8 Jul 264.6 246.4 average 107%
Offshore Islands (district 200)
Cocos Island Airport 29.4 +0.4 31.2 6 Mar 25.1 +0.6 20.9 23 Sep 1464.6 1977.9 low 74%
Varanus Island 29.3 +0.3 37.7 13 Feb 23.7 +0.3 17.0 6 Jul 254.2 259.4 average 98%

Notes

A Annual Climate Summary is prepared to list the main features of the weather in Western Australia using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 2 pm on Wednesday 2 January 2013. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 10 years of record.
The median is sometimes more representative than the mean of long-term average rain.

*Official Perth observations have been recorded at several different sites with varying instrumentation over the years, and these changes can affect the continuity of the climate record. For the current Mt Lawley site, the most significant changes of this kind relate to minimum temperature and rain days.

For that reason, current mean temperature and rain-day data quoted here are based only on readings from the Mt Lawley site, which commenced observations in 1993. Sunshine recordings are from Perth Airport and for similar reasons current means use only Perth Airport data, which commenced in 1993.

For PDF files of Perth Metro climate statistics for other months, please click here for extremes and here for averages.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

Further information

Media
(03) 9669 4057
Enquiries