Western Australia in December 2012: A wet and hot month in southwest WA

  • 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

Rainfall

Rainfall during December 2012 was above- to very-much-above-average through much of western WA, with areas of highest on record in the Southwest and Lower West districts due to extreme rainfall on the 11th and 12th that broke December and all-time records for some sites, as well as the record for the highest daily total in the Southwest Land Division (SWLD) for December. Several sites in the northeast Gascoyne and inland Pilbara also recorded their wettest December as a result of frequent thunderstorm activity during the month. In the remainder of the state, above- to very-much-above-average rainfall was observed in the Eucla and southern Southern Interior, and in the northern Northern Interior and inland Kimberley, while patches of below- to very-much-below-average rainfall were observed in the Southeast Coastal, Goldfields, eastern Interior, and north and west Kimberley.

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.

A trough across northern WA and extending just off the west coast resulted in showers and thunderstorms on the 3rd and 4th over much of northern WA, extending into central parts and the northern SWLD. Severe thunderstorms were observed and Morawa Airport in the Central West registered a wind gust to 94 km/h on the 3rd, while Tenindewa in the Central West recorded 25.2 mm in the 24 hours to 9am on the 4th, which is the site's wettest December day in 11 years of record. Thunderstorms in the Pilbara produced heavy rainfall with 83.4 mm of rain recorded in the 24 hours to 9am on the 4th at Nullagine which produced minor flooding of the Nullagine River.

A deep surface trough across northern and western WA combined with a middle level disturbance to the west, brought showers and thunderstorms to much of northern and western WA on the 5th and 6th. In the 24 hours to 9am on the 6th, Wialki and Bonnie Rock, both in the Central Wheat Belt, observed their wettest December days in 80 and 75 years of record respectively with totals just below 40 mm. The wettest location in the state during the event was the Porongurups in the South Coastal district, which reported 49.0 mm, its wettest December day in 6 years of record.

A trough extending across northern WA and down the west coast resulted in showers and thunderstorms through much of northern and western WA on the 9th and 10th. Heavy rainfall was observed in parts of the Kimberley in the 24 hours to 9am on the 10th, while moderate to heavy totals were observed in the Central West and Central Wheat Belt. Bowgada in the Central West recorded 47.6 mm, which was its second wettest December day in 103 years of record, only behind 52.0 mm recorded on 9 December 1975, while Kondut in the Central Wheat Belt observed its wettest December day in 80 years of record with 43.0 mm. Severe thunderstorms produced strong winds at Dalwallinu in the Central Wheat Belt, with the site observing a maximum wind gust of 104 km/h, while Troughton Island in the Kimberley recorded a maximum wind gust of 91 km/h.

A deep surface trough interacted with a slow moving middle level low off the WA west coast to produce widespread showers and thunderstorms across most of WA from the 10th to 13th. The middle level low was both slow moving, allowing moisture to build up over southwest WA over a period of several days, and in phase with the surface trough, enhancing atmospheric instability. These factors combined to produce unusually heavy rainfall in southwest WA over several days. Very high rainfall totals were reported in the Lower West and Southwest districts on the 11th and 12th, but particularly in northern parts of the Southwest district, around the localities of Bunbury, Harvey, and Collie, with many sites registering December daily records and with some even surpassing their highest monthly total for December. Three daily rainfall reports during the event exceeded the previous highest daily rainfall recorded in the Southwest Land Division (SWLD) for December; a record that was broken in 2011 (i.e., just one year ago) after standing for more than 70 years. The heaviest rainfall was reported during the 24 hours to 9am on the 13th with the highest fall being 210.8 mm at Yourdamung Lake, northeast of Collie in the Southwest district. This is the fifth highest daily rainfall total on record in the SWLD for any month. Please refer to Special Climate Statement 42 for further information. The surface trough and middle level feature responsible for the heavy rainfall moved eastward into central parts of the state on the 13th and 14th, with showers and thunderstorms observed throughout much of southern WA and moderate daily totals reported in the Central Wheat Belt and Eucla, while showers and thunderstorms were observed over much of central and northern WA, with moderate to heavy falls observed in the Kimberley, Pilbara, and north Gascoyne.

Seasonal showers and thunderstorms were a regular feature over northern WA during December 2012, with numerous sites observing daily falls of over 50 mm and several sites in the northeast Gascoyne and inland Pilbara, including Millstream with 111 years of record, observed their wettest December on record. Outside of the extreme rainfall in the Southwest District on the 11th and 12th, the heaviest falls in WA during December 2012 were in the Kimberley where Liveringa Station observed 106.0 mm in the 24 hours to 9am on the 12th, and Mount Hart Station observed 87.0 mm in the 24 hours to 9am on the 16th.

Maximum temperature

Maximum temperatures during December 2012 were well above average throughout much of western and southern WA, and in the north and west Kimberley with daytime temperatures up to 2 °C above normal in most of southern WA, grading to up to 3 °C along parts of the west and south coast, and up to 4 °C above normal the west Eucla and in the west Kimberley near Broome. In contrast, below average maxima were observed through parts of inland northern WA, with daytime temperatures up to 3 °C below normal through inland Pilbara, northwest Gascoyne and southeast Kimberley. Broome in the west Kimberley observed its hottest December in 73 years of record, with a mean maximum temperature of 36.3 °C.

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 sixth hottest December since comparable records commenced in 1950.

A trough across northern WA resulted in hot conditions across northern WA to begin December 2012, with temperatures reaching the low to mid-forties in the Pilbara on the 1st and 2nd. Marble Bar was the hottest location with 45.3 °C. The hot conditions shifted to western WA on the 3rd, with sites in the Central West, Gascoyne and adjacent Pilbara observing maxima in the high thirties to low forties. Geraldton Airport was the hottest location, reaching a maximum of 43.1 °C at 1321 WST, before thunderstorms moved through the area at approximately 1500 WST and temperatures rapidly dropped to the low twenties by 1530 WST. A relatively hot day was observed in western and southern parts of the SWLD on the 4th, with a trough located near the west coast. Conditions were particularly hot in western parts of the Lower West where temperatures were in the mid-to-high thirties, 8 °C to 10 °C above the December average. In contrast, showers and thunderstorms in the Gascoyne resulted in Murchison recording a maximum temperature of 27.9 °C, well below the December mean of 37.3 °C. Perth Metro reached a maximum of 38.2 °C on the 4th, the hottest location in southern WA. A trough across northern WA resulted in very hot day-time maxima on the 9th, with temperatures reaching the mid-forties in the Kimberley. Bidyadanga observed the highest temperature in the state with 45.3 °C, the site's fourth hottest December day on record. West Roebuck's maximum of 45.0 °C was that site's hottest day in December since records commenced in 1999, breaking the previous record of 44.9 °C set on 1 December 2009.

The lowest maximum temperature of the month in WA was recorded at Mt Barker on the 12th as a low pressure system over the SWLD brought showers, thunderstorms and cloud to the region. Southeasterly winds along with cloud and precipitation kept the maximum at the site to just 16.6 °C.

Northerly winds brought hot conditions to the southern Goldfields, Southeast Coastal, and Eucla on the 17th, with temperatures reaching 40 °C at some locations. A broad trough across inland northern WA resulted in hot conditions in parts of the Pilbara, Gascoyne and Interior on the 19th through to the 23rd, extending into the southeastern SWLD on the 21st and Eucla on the 22nd, 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, while Learmonth Airport recording 46.6 °C on the same day which was the second hottest day of the month in WA. A prolonged spell of hot weather was observed in southwestern WA from Christmas Day through to the end of the month, with the hot weather extending across southern WA on the 31st. The hot conditions were due to a stangnant weather system 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 temperatures

Minimum temperatures during December 2012 were above- to very-much-above-average across most of the State, with areas of highest on record in the west Pilbara, east Pilbara and adjacent west Kimberley. Overnight temperatures were up to 2 °C warmer than normal across much of the state, with patches of up to 3 °C above average across central and northwestern parts and a small area of up to 4 °C above normal in the far west Pilbara. In contrast, temperatures were below- to very-much-below-average in the remaining Kimberley and northeastern Northern Interior with an area of up to 2 °C below average in the southwest Kimberley and northeastern Northern Interior. A number of sites in the Pilbara observed their warmest December on record, with several daily December records broken. Particularly high minima were observed on the 29th and 30th in the Lower West and Southwest with several sites breaking December records.

When averaged across WA as a whole, the mean minimum temperature during December 2012 was well above average and ranked as the third warmest December on record. The Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) also saw well above normal overnight minima, with the region observing its fourth warmest December, continuing a run of above average monthly mean minima in which only two months since November 2010 have recorded below average overnight temperatures (May 2012 and July 2012). Comparable temperature records commenced in 1950.

A ridge developed along the south coast to begin December 2012, resulting in cool mornings over much of southern WA from the 1st to 3rd. WA's coolest temperature for December 2012 occurred on the 1st, with Wandering in the Great Southern observing a minimum of just 3.8 °C. A warm morning was observed in southern parts of the SWLD on the 5th, with minimum temperatures in the Great Southern and Central Wheat Belt in the low twenties, well above the December average, which is generally in the low to mid-teens. Warm conditions were observed in northern WA on the 9th and 10th, with temperatures in the high-twenties to low-thirties at some locations in the Pilbara and Kimberley. Fitzroy Crossing Aerodrome recorded a minimum temperature of 31.1 °C on the 9th, which was its second highest December minimum since records commenced in 1997, only behind a minimum of 32.1 °C on 15 December 2009. Mandora observed the highest minimum temperature in the state on the 10th with 30.7 °C, which was its second hottest night in December in 47 years of record, and its hottest night since its December record was set at 32.4 °C on 12 December 1993. Warm minima were experienced in northern parts of WA on the morning of the 24th, with minimum temperatures in the Pilbara and Kimberley in the high twenties to low thirties. Emu Creek Station observed its warmest December night in 40 years of record with 32.7 °C which was also the warmest night in December 2012. Learmonth also observed their warmest December minimum with 29.2 °C. The warm overnight conditions continued through much of central and southwestern WA through to the end of the month, complimenting the hot daytime temperatures. Particularly warm minima were observed on the 29th in the Lower West and Southwest districts, where Perth Airport and Karnet observed their warmest December minima in 59 and 47 years of record respectively, while the 24.3 °C at Cape Naturaliste on the 30th was their equal highest December minima in 56 years of record.

Tropical Cyclones

Tropical cyclone Mitchell formed out of a low well to the northwest of the Pilbara coast during the morning of the 29th. 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 December 2012
Hottest day 47.3 °C at Emu Creek Station on the 23rd
Warmest days on average 40.7 °C at Marble Bar
Coolest days on average 22.3 °C at Albany
Coldest day 16.6 °C at Mount Barker on the 12th
Coldest night 3.8 °C at Wandering on the 1st
Coolest nights on average 12.3 °C at Jacup
Warmest nights on average 27.3 °C at Broome Airport
Warmest night 32.7 °C at Emu Creek Station on the 24th
Wettest overall 258.6 mm at Mount Hart Station
Wettest day 210.8 mm at Yourdamung Lake on the 13th
Highest wind gust 104 km/h at Dalwallinu on the 9th

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 December daily rainfall
Highest daily rainfall
in December 2012 (mm)
Previous wettest
for December
Years of
record
Collie 157.2 on the 13th 42.0 on the 24th in 1987 106
Wilgarrup 48.2 on the 11th 47.0 on the 25th in 1925 106
Brunswick Junction 77.6 on the 12th 33.1 on the 28th in 1984 104
Boyanup 68.8 on the 13th 45.0 on the 4th in 2001 102
Wialki 39.0 on the 6th 35.1 on the 7th in 1958 80
Kondut 43.0 on the 10th 40.2 on the 17th in 2007 78
Bonnie Rock 38.0 on the 6th 35.6 on the 19th in 1978 75
Roelands 75.2 on the 12th 37.8 on the 31st in 1959 71
Ferguson Valley 87.0 on the 13th 33.0 on the 4th in 2001 41
Medina Research Centre 35.6 on the 12th 26.8 on the 13th in 2011 30



Record highest total December rainfall
Total rainfall
for December 2012 (mm)
Previous wettest
for December
Years of
record
Average for
December
Collie 170.4 80.6 in 1913 114 17.4
Boyanup 117.2 82.2 in 1913 112 16.0
Millstream 137.1 129.0 in 1988 111 29.2
Wilgarrup 81.6 81.3 in 1944 109 21.7
Brunswick Junction 100.4 64.3 in 1944 104 15.6
Trayning 78.0 77.6 in 2011 102 12.3
Turee Creek 133.0 130.3 in 1975 88 23.9
Roelands 132.6 61.2 in 1944 71 16.4
Neds Creek 77.8 72.6 in 1995 66 17.0
Wokalup 60.8 54.4 in 1951 60 15.7
Yalleen 139.3 110.6 in 2000 53 26.4
Mininer 90.7 88.0 in 1975 49 17.4
Ferguson Valley 142.8 68.4 in 2001 41 17.9
Mosman Park 41.2 33.9 in 1991 35 6.6
Medina Research Centre 56.2 51.8 in 2011 30 12.1



Record highest December temperature
Highest temperature
in December 2012 (°C)
Previous warmest
for December
Years of
record
Average for
December
Cape Naturaliste 37.7 on the 30th 37.6 on the 26th in 2007 56 23.6
Jarrahwood 40.5 on the 30th = 40.5 on the 26th in 2007 30 26.9



Record highest December mean daily maximum temperature
Mean daily maximum
temperature
for December 2012 (°C)
Previous warmest
for December
Years of
record
Average for
December
Broome Airport 36.3 36.0 in 1951 73 33.8



Record highest December daily minimum temperature
Highest daily minimum
temperature
in December 2012 (°C)
Previous warmest
for December
Years of
record
Average for
December
Perth Airport 27.5 on the 29th 26.9 on the 24th in 1960 69 14.9
Cape Naturaliste 24.3 on the 30th = 24.3 on the 26th in 2007 56 13.9
Bidyadanga 30.0 on the 9th 29.6 on the 24th in 2006 54 25.7
Karnet 23.5 on the 29th 22.6 on the 29th in 2009 47 13.4
Emu Creek Station 32.7 on the 24th 32.3 on the 21st in 2004 41 22.3
Learmonth Airport 29.2 on the 24th 27.6 on the 30th in 1994 38 20.8



Record highest December mean daily minimum temperature
Mean daily minimum
temperature
for December 2012 (°C)
Previous warmest
for December
Years of
record
Average for
December
Port Hedland Airport 26.6 26.1 in 1962 64 24.0
Bidyadanga 27.1 = 27.1 in 2002 53 25.7
Mandora 26.5 26.3 in 1990 47 24.3
Onslow Airport 25.3 24.7 in 1973 46 22.2
Narembeen 16.8 = 16.8 in 1977 44 14.4
Emu Creek Station 24.8 24.7 in 1979 40 22.3
Telfer Aero 26.9 26.7 in 2003 38 25.3
Learmonth Airport 23.3 23.0 in 2010 37 20.8



Summary statistics for December 2012
Maximum temperatures
for December
(°C)
Minimum temperatures
for December
(°C)
Rainfall
for December
(millimetres)
Mean for
December
2012
Diff
from
average
Highest for
December
2012
Mean for
December
2012
Diff
from
average
Lowest for
December
2012
Total for
December
2012
Average
for
December
Rank of
December
2012
Fraction of
December
average
North Kimberley (district 01)
Doongan 34.5 0.0 38.0 8th 22.5 -0.6 17.9 10th 228.2 222.7 average 102%
Kalumburu 35.4 +0.1 38.6 6th 24.5 -0.5 22.3 7th 219.8 235.8 average 93%
Mount Elizabeth 34.3 +0.2 39.3 8th 22.1 -0.2 20.4 27th 195.1 166.9 high 117%
Truscott 35.5   37.8 6th 26.2   20.9 25th  
Wyndham 38.0 -0.2 42.9 7th 26.4 -0.6 21.7 27th 186.7 151.0 high 124%
Wyndham Aero 38.6 +0.7 43.8 7th 26.2 -0.6 21.5 27th 138.2 129.5 average 107%
East Kimberley (district 02)
Argyle Aerodrome 38.1 +0.9 44.0 7th 25.4 -0.5 21.4 19th        
Halls Creek Airport 37.5 -0.3 43.5 8th 24.2 -0.5 20.4 19th 83.0 82.2 average 101%
Kununurra Aero 38.1 +1.0 43.2 6th 24.8 -0.6 20.6 27th 153.2 135.9 average 113%
Warmun 37.8 -0.6 42.7 8th 24.6 -0.6 21.6 19th 177.0 115.2 high 154%
West Kimberley (district 03)
Bidyadanga 37.5 +2.6 45.3 9th 27.1 +1.4 23.5 23rd 121.4 54.9 high 221%
Broome Airport 36.3 +2.5 43.0 9th 27.3 +0.8 22.6 29th 25.4 55.6 average 46%
Curtin Aero 39.0 +0.6 43.4 8th 24.8 -0.2 22.0 22nd 195.6 149.0 average 131%
Cygnet Bay 35.4 +0.6 38.7 5th 25.7 +0.3 22.5 25th 71.0 75.4 average 94%
Derby Aero 38.4 +1.3 43.3 8th 25.8 -0.5 22.6 3rd 77.4 70.1 average 110%
Fitzroy Crossing Aero 39.7 +0.6 45.0 8th 25.6 -0.1 22.0 22nd 130.6 122.6 average 107%
West Roebuck 37.8 +2.0 45.0 9th 26.1 +0.8 22.3 29th 66.8 101.1 low 66%
De Grey (district 04)
Karratha Aero 36.6 +0.9 41.1 24th 27.1 +1.7 19.8 1st 4.6 12.5 average 37%
Legendre Island 33.1   35.5 7th 26.8   24.0 1st
Mandora 38.4 +1.7 43.3 9th 26.5 +2.2 23.0 12th 6.0 33.5 average 18%
Marble Bar 40.7 -1.0 45.3 24th 26.2 +0.1 20.9 15th        
Pardoo Station 37.9 +1.6 42.0 9th 26.4 +1.7 21.0 12th 13.2 23.5 average 56%
Port Hedland Airport 37.6 +1.0 42.7 10th 26.6 +2.6 19.7 1st 0.2 17.9 average 1%
Roebourne 39.1 +0.1 44.6 24th 26.7 +1.8 21.0 1st 14.4 11.0 high 131%
Roebourne Aero 39.0 -0.2 44.4 24th 26.3 +1.7 19.4 1st 19.4 6.8 high 285%
Fortescue (district 05)
Barrow Island Airport 34.4 +2.4 38.8 24th 26.2 +1.9 23.4 2nd 53.2 6.6 v high 806%
Learmonth Airport 37.8 +1.0 46.6 23rd 23.3 +2.5 16.5 1st 10.6 6.6 high 161%
Mardie 37.8 +0.2 42.3 24th 25.9 +3.0 18.4 1st        
Onslow Airport 36.8 +0.9 41.4 10th 25.3 +3.1 21.1 2nd 7.0 3.6 high 194%
Wittenoom 38.3 -1.3 44.5 24th 24.9 -0.6 20.1 13th 64.4 49.6 high 130%
West Gascoyne (district 06)
Carnarvon Airport 30.6 +1.3 39.9 28th 21.8 +1.2 16.9 1st 14.4 5.7 v high 253%
Denham 30.2 +1.1 38.0 28th 21.4 +1.0 17.4 31st 12.2 2.4 v high 508%
Emu Creek Station 40.1 +0.3 47.3 23rd 24.8 +2.5 19.0 1st 20.5 13.3 high 154%
Shark Bay Airport 32.9 +0.8 39.2 29th 20.5 +0.9 15.4 1st 13.6 12.9 high 105%
East Gascoyne (district 07)
Newman Aero 36.9 -2.1 44.4 24th 23.7 -0.1 18.9 6th 81.0 38.0 v high 213%
Paraburdoo Aero 38.6 -1.7 44.6 23rd 24.4 0.0 20.4 6th 33.6 28.7 high 117%
Murchison (district 07A)
Meekatharra Airport 35.8 -0.6 42.8 24th 22.7 +0.7 15.7 1st 78.2 14.5 v high 539%
Mount Magnet Aero 36.6 +1.2 44.1 21st 22.3 +1.3 13.5 1st 28.4 24.6 average 115%
North Coast (district 08)
Carnamah 35.2 +1.7 43.8 26th 18.4 +2.4 9.6 1st 16.2 9.2 high 176%
Dalwallinu 33.7 +0.6 42.6 26th 17.0 +1.3 7.0 1st 45.2 16.0 v high 283%
Geraldton Airport 32.6   43.9 31st 17.9   10.1 1st 15.4
Geraldton Airport Comparison 32.5 +3.0 42.8 3rd 17.8 +1.5 9.3 1st        
Kalbarri 33.0 +1.9 42.0 3rd 19.1 +1.7 10.5 2nd 5.2 4.0 high 130%
Morawa Airport 35.3 +0.2 43.7 26th 18.9 +1.6 9.2 1st 56.8 16.3 v high 348%
Mullewa 35.8 +1.4 44.5 26th 19.7 +2.7 11.3 1st 10.6 8.4 high 126%
Wongan Hills 33.8 +1.4 42.2 26th 17.8 +2.0 7.7 1st 16.8 10.2 high 165%
Central Coast (district 09)
Badgingarra Research Stn 32.9 +0.9 41.8 26th 16.7 +1.7 7.1 1st        
Bickley 29.2 +1.3 38.6 31st 15.4 +1.9 8.2 1st 36.2 13.8 high 262%
Champion Lakes 30.6   40.8 31st 18.1   9.6 1st 75.6
Garden Island HSF 27.0 +1.6 36.6 30th 18.5 +1.4 13.2 1st 52.0 13.3 v high 391%
Gingin Aero 31.7 +1.2 41.5 31st 15.8 +1.5 7.8 1st 57.6 10.8 v high 533%
Gosnells City 32.3 +2.0 43.0 31st         25.4 11.7 high 217%
Jandakot Aero 30.7 +1.8 41.2 31st 16.4 +1.8 6.6 8th 28.8 11.0 v high 262%
Jurien Bay 30.6 +2.5 42.0 31st 16.7 +1.1 9.0 8th 23.8 7.2 v high 331%
Karnet 29.1 +0.9 38.9 31st 15.2 +1.8 5.2 1st 31.6 18.5 high 171%
Lancelin 29.7 +2.4 41.5 31st 17.3 +1.1 11.5 8th 33.4 8.4 v high 398%
Pearce RAAF 32.7 +2.5 42.7 31st 16.4 +1.9 6.7 1st 42.8 10.8 v high 396%
Perth Airport 31.4 +2.5 42.2 31st 16.8 +1.9 6.2 1st 22.8 11.4 high 200%
Perth Metro* 31.2 +2.3 42.1 31st 17.8 +1.5 9.4 8th 20.2 13.3 v high 151%
Rottnest Island 26.8 +1.8 37.5 31st 18.8 +1.3 14.4 1st 27.6 8.2 v high 337%
Swanbourne 30.0 +2.2 40.6 31st 17.9 +1.4 11.4 8th 52.2 12.9 v high 405%
South Coast (district 09A)
Albany 22.3 +0.4 30.3 5th 15.6 +1.6 8.9 28th 53.2 29.9 high 178%
Albany Airport 24.6   32.9 25th 13.4   6.9 2nd 54.0
Albany Airport Comparison 24.5 +1.4 33.1 30th 13.4 +0.9 7.1 9th 41.6 27.8 high 150%
Bridgetown 28.8 +1.5 40.3 31st 12.8 +1.8 5.8 2nd 72.0 20.6 high 350%
Bunbury 27.8 +0.6 39.2 30th 15.4 +1.9 5.4 1st 121.4 21.7 v high 559%
Busselton Aero 29.3 +1.4 41.0 30th 14.3 +1.9 4.9 1st 27.2 10.4 high 262%
Cape Leeuwin 23.3 +1.5 29.7 31st 17.3 +1.5 13.7 1st 9.4 20.9 low 45%
Cape Naturaliste 26.7 +3.1 37.7 30th 15.8 +1.9 11.1 2nd 7.6 13.4 average 57%
Collie East 29.3 +1.0 39.4 30th 13.1 +1.6 4.5 1st 155.0 26.9 v high 576%
Donnybrook 29.2 +1.0 38.8 28th 14.5 +2.1 5.6 1st 81.5 16.6 v high 491%
Dwellingup 29.3 +2.1 39.5 31st 14.4 +1.9 4.3 1st 50.6 20.9 v high 242%
Esperance 26.3 +1.8 38.8 31st 15.2 +0.8 8.8 2nd 15.4 18.8 average 82%
Esperance Aero 28.5 +3.0 39.6 21st 14.2 +0.8 8.3 2nd 19.6 20.4 average 96%
Harvey 29.9 +1.5 40.0 30th         75.4 19.1 v high 395%
Hopetoun North 23.2 -1.0 28.6 25th         9.6 25.2 average 38%
Jarrahwood 29.2 +2.3 40.5 30th 13.3 +2.2 4.0 1st 43.0 17.5 v high 246%
Mandurah 28.6 +1.9 38.4 28th 18.8 +1.8 12.7 1st 80.0 20.9 high 383%
Manjimup 27.8 +3.0 40.6 30th 13.4 +1.7 7.8 8th 41.6 25.5 high 163%
North Walpole 24.1   35.9 31st 14.0   9.1 9th 54.8
Pemberton 26.6 +2.8 39.6 31st 13.5 +1.6 7.1 1st 38.2 34.7 average 110%
Rocky Gully 28.4 +3.1 40.9 30th 12.5 +1.4 6.0 2nd 23.0 31.8 average 72%
Windy Harbour 22.8 +0.9 31.3 31st 14.7 +1.6 9.0 20th 41.3 28.7 high 144%
Witchcliffe 27.3 +2.7 40.6 30th 13.7 +1.4 7.6 2nd 32.6 15.8 high 206%
North Central (district 10)
Bencubbin 33.5 +1.1 42.4 26th 18.0 +2.1 9.4 1st 23.9 13.5 high 177%
Cunderdin Airfield 34.4 +1.8 42.7 26th 16.7 +1.9 6.3 1st 20.2 9.1 high 222%
Kellerberrin 33.6 +1.6 42.1 30th 16.3 +1.3 6.3 1st 29.5 13.5 high 219%
Merredin 33.6 +1.7 42.5 26th 17.3 +1.6 8.5 1st 35.0 14.3 high 245%
Northam 33.8 +1.7 42.2 26th 16.5 +1.2 6.3 1st 23.3 9.4 high 248%
York 33.8 +1.8 42.0 31st 15.5 +1.5 5.0 1st 16.6 12.5 average 133%
South Central (district 10A)
Beverley 34.0 +1.9 42.2 31st 16.1 +1.7 5.6 1st 10.6 10.4 average 102%
Brookton 33.0 +2.1 41.4 31st 15.5 +2.1 4.1 1st 2.7 10.4 average 26%
Corrigin 32.8 +2.4 41.6 31st 16.2 +2.2 5.0 1st 8.7 13.1 average 66%
Hyden 33.2 +1.5 42.0 31st 15.9 +2.1 6.5 1st 12.2 15.1 average 81%
Jacup 28.7 +2.9 39.7 21st 12.3 +0.8 4.8 1st 25.8 27.6 average 93%
Katanning 30.7 +2.4 40.5 30th 13.4 +1.7 6.0 1st 78.2 27.9 high 280%
Lake Grace 31.4 +2.2 40.6 31st 15.2 +1.8 6.8 1st 28.8 20.4 average 141%
Narembeen 33.7 +1.8 41.9 26th 16.8 +2.4 7.8 1st 17.5 13.1 high 134%
Narrogin 30.9 +2.0 40.5 30th 14.9 +2.6 4.9 1st 29.6 14.2 high 208%
Newdegate Research Station 31.4 +2.3 40.8 21st 13.5 +1.8 4.2 1st 11.6 15.2 average 76%
Ongerup 29.3 +2.2 39.0 30th 13.8 +1.4 5.8 1st 40.4 17.4 v high 232%
Pingelly 32.0 +2.1 40.6 31st 15.7 +1.8 6.9 8th 8.4 12.6 average 67%
Ravensthorpe 28.7 +1.5 40.0 21st 13.8 +1.0 6.9 1st 13.1 23.5 average 56%
Wagin 30.9 +1.7 40.7 30th 14.9 +2.0 6.4 1st 67.0 13.2 v high 508%
Wandering 31.8 +1.7 41.1 30th 13.7 +1.8 3.8 1st 22.2 19.5 high 114%
Eucla (district 11)
Balladonia 31.8 +1.6 42.2 31st 14.3 +1.0 9.5 1st 8.2 18.4 average 45%
Eucla 28.2 +3.4 41.0 7th 15.9 +0.9 8.0 2nd 48.0 18.5 v high 259%
Eyre 29.0 +3.7 45.4 22nd 13.3 -0.8 4.0 2nd 43.4 20.3 high 214%
Forrest 33.2 +2.0 43.6 22nd 15.1 +0.3 10.3 5th 19.0 26.4 average 72%
Red Rocks Point 25.1 +1.1 39.2 22nd 16.8 +0.5 9.0 2nd 43.8 20.6 high 213%
South East (district 12)
Bulga Downs 36.8 +1.1 42.3 22nd 21.5 +1.6 13.0 1st 33.0 13.6 high 243%
Kalgoorlie-Boulder Airport 33.6 +1.7 40.9 31st 18.6 +2.0 10.9 1st 6.2 16.3 average 38%
Laverton Aero 35.7 +2.4 43.8 22nd 21.7 +2.2 15.3 1st 32.6 28.5 average 114%
Leinster Aero 36.4 +1.3 43.0 22nd 23.3 +2.4 15.5 1st 27.4 28.5 average 96%
Leonora         21.8 +1.8 14.8 1st 17.6 16.8 average 105%
Leonora Aero 36.3   43.1 22nd 22.1   15.3 1st 17.8
Munglinup West 29.4 +2.2 40.6 21st 13.7 +1.1 7.1 1st 12.6 25.8 average 49%
Norseman Aero 32.6 +1.8 41.6 31st 15.0 +1.2 5.9 1st 13.6 24.6 average 55%
Salmon Gums Res.Stn. 30.8 +1.9 41.3 31st 13.2 +1.0 5.1 2nd 9.6 20.1 average 48%
Southern Cross Airfield 34.2 +1.6 43.8 21st 17.6 +2.4 9.7 1st 21.6 17.6 high 123%
North East (district 13)
Carnegie 37.3 0.0 44.6 23rd 24.2 +2.3 19.6 13th 7.9 23.8 average 33%
Giles Meteorological Office 36.4 +0.7 43.8 24th 23.1 +1.3 17.9 10th 36.8 45.1 average 82%
Telfer Aero 40.0 -0.2 45.5 24th 26.9 +1.6 21.0 13th        
Warburton Airfield 38.3 +1.8 44.6 23rd 23.7 +2.5 21.2 6th 10.2 31.5 average 32%
Wiluna 37.2 +0.4 44.0 23rd 22.9 +1.8 15.0 1st 28.8 22.3 high 129%
Offshore Islands (district 200)
Christmas Island Aero 28.5 +0.8 30.6 28th                
Cocos Island Airport 29.3 -0.1 30.4 31st 25.4 +0.8 23.3 5th 125.2 115.6 high 108%
Varanus Island 32.7 +1.5 35.2 10th 26.2 +1.5 23.8 1st 6.8 2.4 high 283%

Notes

A Monthly 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 9 am 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