Western Australia in April 2012: A warm dry month for southern WA

  • Rainfall: below average for WA
  • Maximum temperature: near average for WA; above average for southwest WA
  • Minimum temperature: below average for WA; above average for southwest WA

Rainfall

Rainfall during April 2012 was below to very much below average in much of the southern half of WA, particularly in eastern parts of the Southwest Land Division (SWLD) and western parts of the Goldfields. Western parts of the SWLD including the Perth Metropolitan area saw heavy rainfall during the last few days of the month to record near average or above average April rainfall. In the north of the state, rainfall was mostly near average, with small areas of below average rainfall in the Gascoyne and west Pilbara. Rainfall in the Kimberley was a mixture of above and below average, with a generally quiet month to end the wet season apart from some heavy rainfall towards the end of the month in eastern parts. When averaged across the state, April 2012 rainfall was below average, whilst the Lower Southwest (southwest a line from Jurien Bay to Bremer Bay) and SWLD also experienced below average rainfall.

A westerly flow over the south of the state brought light to moderate showers during the first few days of April 2012 before a strong high moved into the Bight on the 6th. A stagnant trough over central parts of the state early in April caused showers and thunderstorms in central and northern parts, contracting to the Kimberley on the 10th and mostly clearing on the 11th. Generally dry conditions then persisted across much of WA, aside from a few isolated thunderstorms in central parts, before a series of weak fronts moved across southern WA from the 18th to 21st, causing generally light falls. Showers and thunderstorms returned to the Kimberley from the 20th to 25th, with heavy falls in eastern parts of the district on the 23rd and 24th. The heaviest daily totals in WA for April 2012 were observed during this period, with 104.2 mm at El Questro in the 24 hours to 9am on the 24th breaking the April record at the site of 89.6 mm set on 4 April 2011. Another strong high moved into the Bight on the 23rd, maintaining dry conditions over the south for the next few days, and clearing the storms in the Kimberley on the 26th. A low to the west of the state and a rainband brought moderate to heavy falls to the southwest of WA on the 28th and 29th, particularly in the Lower West and Southwest districts.

Rainfall in WA during the 2011/12 northern wet season (October-April) was generally above to very much above average, with small areas of highest on record in the southwest Kimberley and northeast Gascoyne. Sites in the southeast Central Wheat Belt and eastern Great Southern also saw their wettest October to April period, mainly due to a wet October and very heavy rainfall during early December. Dampier Downs in the west Kimberley observed its highest wet season rainfall total with 864.4 mm, breaking its previous record of 839.4 mm set in 1977/78. Two tropical cyclones crossed the Pilbara coast during the season, TC Heidi in early January and TC Lua in mid March, whilst TC Iggy also affected the WA mainland in late January and early February before crossing the Central West coast as a tropical low. A strong monsoon burst, associated with TC Iggy off the northwest coast, brought very heavy rainfall to the west Kimberley, with Cygnet Bay and Cape Leveque recording four consecutive days of over 100 mm, from 26 to 29 January. Such a sequence of four consecutive days over 100 mm had not been recorded before in WA. The highest daily rainfall total for the 2011/12 wet season in WA was 260.6 mm at Troughton Island in the north Kimberley, whilst Doongan observed the highest total for the wet season with 1798.2 mm, followed by Kalumburu with 1411.4 mm.

Maximum temperature

Much of southern and western WA, as well as the Interior, saw above to very much above average maximum temperatures in April 2012, with areas up to 3 °C warmer than normal in the eastern SWLD, southwest Gascoyne, Eucla, and southern Interior. Eyre in the Eucla observed its warmest April in 52 years of record with a mean maximum temperature of 26.6 °C which is 2.6 °C above the long-term mean. Below average maximum temperatures were confined to the east Kimberley and coastal parts of the east Pilbara and far west Kimberley, with an area of up to 2 °C below normal in the east Kimberley. When averaged across the state, the mean maximum temperature for WA during April 2012 was near average, whilst the mean maximum temperature over the Lower Southwest was above average.

Unseasonally hot conditions were observed in the Interior and adjacent Eucla to start the month, with Giles observing its equal hottest April day on record as it registered a maximum temperature of 38.3 °C on the 1st. The hot conditions persisted until the 6th when a high in the Bight brought a cooler southeasterly flow. Hot days were also observed in the southwest of the state from the 9th to 11th due to warm northeasterly winds. A ridge developed along the south coast on the 22nd in the wake of a cold front, resulting in the coldest day for the month in WA being recorded at Ravensthorpe in the Southeast Coastal district with a maximum of 14.4 °C. Relatively low temperatures were observed across much of the north of the state from the 24th through to the end of the month due to a strong high in the Bight directing a cool southeasterly flow over the area.

Minimum temperature

April 2012 saw much of WA experiencing near average mean minimum temperatures. Areas of below to very much below average minima were evident in much of the Kimberley, inland Pilbara, east Gascoyne and northern Goldfields, with an area of up to 3 °C cooler than normal minima in the northern Goldfields. Above average overnight temperatures were observed in western and southern parts of the SWLD, parts of the eastern Interior, eastern Eucla, and west Pilbara with up to 2 °C warmer than normal mean minimum temperatures along parts of the SWLD coast and up to 4 °C warmer than normal minima in the northeast Interior.

A stagnant airmass over the east of the state to begin the month resulted in warm nights in the Interior and adjacent east Eucla, before a strong high moved into the Bight and directed cool southeast winds over the area on the 7th. A strong high moved into the Bight in the wake of a cold front on the 23rd, 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, beating the previous record of 15.9 °C set only last year, while several sites with shorter periods of record also observed their coolest April night on the 30th.

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Extremes in April 2012
Hottest day 42.0 °C at Roebourne on the 3rd
Warmest days on average 36.9 °C at Mardie
Coolest days on average 22.0 °C at Windy Harbour
Coldest day 14.4 °C at Ravensthorpe on the 22nd
Coldest night -0.1 °C at Eyre on the 25th
Coolest nights on average 9.5 °C at Newdegate Research Station
9.5 °C at Salmon Gums Res.Stn.
Warmest nights on average 26.7 °C at Troughton Island
23.3 °C at Truscott
Warmest night 28.5 °C at Troughton Island on the 21st
27.5 °C at Karratha Aero on the 6th
Wettest overall 132.0 mm at Witchcliffe
Wettest day 104.2 mm at El Questro on the 24th
Highest wind gust 85 km/h at Cape Leeuwin on the 1st
85 km/h at North Walpole on the 3rd

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

Click on a map to show it full size in a pop-up window



Record highest April temperature
Highest temperature
in April 2012 (°C)
Previous warmest
for April
Years of
record
Average for
April
Giles Meteorological Office 38.3 on the 1st = 38.3 on the 1st in 2009 56 29.4



Record highest April mean daily maximum temperature
Mean daily maximum
temperature
for April 2012 (°C)
Previous warmest
for April
Years of
record
Average for
April
Eyre 26.6 26.2 in 1994 52 24.0



Record lowest April temperature
Lowest temperature
in April 2012 (°C)
Previous coolest
for April
Years of
record
Average for
April
Wyndham 15.7 on the 30th 15.9 on the 21st in 2011 45 23.6



Summary statistics for April 2012
Maximum temperatures
for April
(°C)
Minimum temperatures
for April
(°C)
Rainfall
for April
(millimetres)
Mean for
April
2012
Diff
from
average
Highest for
April
2012
Mean for
April
2012
Diff
from
average
Lowest for
April
2012
Total for
April
2012
Average
for
April
Rank of
April
2012
Fraction of
April
average
North Kimberley (district 01)
Doongan 32.3 -0.8 35.0 7th 18.1 -0.9 9.5 28th 17.0 49.3 average 34%
Kalumburu 34.2 -0.4 36.8 20th 20.6 -0.5 11.4 29th 16.6 41.7 average 40%
Mount Elizabeth 32.5 0.0 34.7 21st 16.5 -0.2 6.9 28th 15.6 39.6 average 39%
Troughton Island 32.3 -0.4 33.8 16th 26.7 -0.1 23.7 1st 12.2 31.2 average 39%
Truscott 32.2   34.1 19th 23.3   17.0 29th 20.6
Wyndham 34.4 -1.5 37.5 4th 22.7 -0.9 15.7 30th 2.8 35.4 low 8%
Wyndham Aero 35.3 -1.3 38.3 20th 22.7 -0.8 14.8 27th 6.4 27.8 average 23%
East Kimberley (district 02)
Argyle Aerodrome 33.7 -1.2 37.6 6th 21.4 -1.4 14.3 27th 64.0 24.9 high 257%
Halls Creek Airport 32.2 -1.6 37.3 4th 19.1 -1.3 11.6 28th 57.0 21.5 high 265%
Kununurra Aero 34.2 -1.1 37.1 5th 20.8 -1.2 11.9 30th 15.0 28.0 average 54%
Warmun 34.0 -1.1 38.0 7th 19.6 -1.0 12.5 27th 35.0 25.1 high 139%
West Kimberley (district 03)
Bidyadanga 35.0 -0.7 38.2 9th 21.7 -0.4 15.5 28th 22.8 25.4 high 90%
Broome Airport 33.6 -0.7 36.6 8th 21.8 -0.8 12.7 28th 3.2 26.4 average 12%
Curtin Aero 35.6 -0.8 38.4 4th 21.5 -0.8 14.0 30th 1.2 46.4 low 3%
Cygnet Bay 32.6 -1.0 34.9 2nd 21.8 -0.5 14.2 28th 36.8 39.8 high 92%
Derby Aero 34.5 -1.0 37.2 7th 21.8 -1.0 13.7 29th 0 26.1 lowest 0%
Fitzroy Crossing Aero 35.5 -1.1 38.7 7th 19.6 -1.1 10.9 28th 0 33.6 v low 0%
West Roebuck 34.9 -0.4 37.8 5th 20.9 -0.8 12.3 28th 7.6 37.8 average 20%
De Grey (district 04)
Bedout Island 30.9   33.0 9th     25.0 29th
Karratha Aero 34.7 +0.5 39.6 3rd 21.8 -0.8 16.3 13th 0.6 17.9 average 3%
Legendre Island 32.3   35.3 18th 25.1   21.8 29th
Mandora     38.3 5th 20.0 -0.8 12.8 29th 8.0 20.3 average 39%
Marble Bar 35.4 -0.8 39.4 3rd 20.9 -1.3 12.1 28th 6.4 19.3 average 33%
Pardoo Station 34.8 -0.7 38.7 2nd 21.4 -0.2 14.6 26th 4.8 19.2 high 25%
Port Hedland Airport 34.5 -0.7 38.1 2nd 20.7 -0.7 14.7 28th 2.2 22.4 average 10%
Roebourne 36.2 +0.9 42.0 3rd 21.6 -0.6 16.7 30th 0.6 28.5 average 2%
Roebourne Aero 35.8 -0.4 41.1 3rd 20.1 -1.9 14.0 28th 0.4 6.2 average 6%
Fortescue (district 05)
Barrow Island Airport 31.2 +0.2 34.3 8th 24.6 +0.1 20.7 28th 0.6 44.8 low 1%
Learmonth Airport 34.5 +1.3 38.4 9th 19.3 -1.1 15.1 28th 0 15.7 lowest 0%
Mardie 36.9 +1.1 40.8 8th 20.6 -0.4 16.5 13th 0 19.7 lowest 0%
Onslow 34.3 +1.1 37.9 18th 22.2 +1.8 19.0 28th 0 20.1 lowest 0%
Onslow Airport 35.6 +1.9 39.0 4th 21.8 +0.5 17.5 28th 0 12.0 lowest 0%
Thevenard Island 32.7 +0.9 35.4 5th 23.8 -0.5 18.4 29th 0.2 23.3 v low 1%
Wittenoom 33.7 +0.6 37.6 3rd 20.5 -0.7 13.3 28th 1.8 28.3 low 6%
West Gascoyne (district 06)
Carnarvon Airport 30.8 +1.8 37.8 10th 18.8 -0.3 13.6 23rd 6.4 14.1 average 45%
Denham 29.2 +0.7 37.2 10th 20.4 +0.8 15.0 23rd 0 14.1 lowest 0%
Emu Creek Station 35.0 +0.1 38.2 7th 20.0 -0.8 16.0 14th 14.6 20.4 average 72%
Murchison 31.7 +0.9 38.8 7th 14.7 -1.5 8.1 23rd 9.6 23.1 average 42%
Shark Bay Airport 31.7 +0.9 38.8 9th 17.9 -0.2 14.7 18th 0 10.0 v low 0%
East Gascoyne (district 07)
Newman Aero 31.7 0.0 35.9 3rd 16.1 -1.3 9.0 28th 18.0 19.9 average 90%
Paraburdoo Aero 33.2 -0.2 36.6 3rd 18.2 -1.5 11.6 28th 17.4 26.8 average 65%
Murchison (district 07A)
Meekatharra Airport 29.3 +0.1 34.1 4th 15.6 -1.5 9.7 23rd 0.6 20.2 low 3%
Mount Magnet Aero 29.1 +0.4 34.1 16th 15.4 -0.7 9.7 23rd 19.4 21.7 average 89%
North Coast (district 08)
Carnamah 28.4 +0.8 35.7 12th 14.4 +0.4 8.7 21st 9.6 22.5 average 43%
Dalwallinu 27.6 +0.6 33.2 10th 12.9 -0.2 7.0 21st 1.4 10.0 low 14%
Dalwallinu Comparison 27.7 +1.0 33.9 10th 13.7 +0.2 7.9 21st 1.9 20.6 v low 9%
Geraldton Airport 29.0   37.6 10th 15.4   10.5 23rd 11.4
Geraldton Airport Comparison 28.8 +1.1 37.4 10th 15.5 +0.1 10.1 23rd 11.6 23.7 average 49%
Kalbarri 30.4 +1.0 38.5 10th 16.2 0.0 12.2 17th 44.3 18.8 high 236%
Morawa Airport 29.5 +0.7 35.7 7th 13.9 -0.4 7.8 22nd 4.4 13.4 average 33%
Mullewa 29.7 +1.0 35.5 10th 15.2 +0.2 10.1 18th 11.0 21.1 average 52%
North Island 27.5 +1.4 33.4 10th 20.6 +0.4 14.9 26th 11.2 15.2 high 74%
Wongan Hills 27.5 +1.2 34.2 10th 13.7 +0.4 6.5 21st 7.4 22.3 low 33%
Central Coast (district 09)
Badgingarra Research Stn 27.4 +0.2 35.2 10th 14.0 +0.5 8.8 22nd 6.8 27.3 low 25%
Bickley 23.3 -0.2 32.1 10th 13.3 +0.8 6.6 6th 78.8 56.2 average 140%
Champion Lakes 25.4   34.3 10th 15.5   9.9 21st 68.2
Garden Island HSF 24.2 +0.5 29.5 10th 16.5 +0.7 11.8 6th 47.4 44.8 average 106%
Gingin Aero 27.0 +0.4 36.0 10th 12.7 +0.9 5.7 21st 39.2 29.4 average 133%
Jandakot Aero 26.0 +0.3 34.6 10th 12.7 +0.4 6.9 21st 69.4 43.5 high 160%
Jurien Bay 26.9 +0.6 34.2 11th 15.5 +1.5 9.6 23rd 23.2 29.5 average 79%
Karnet 23.4 +0.2 32.2 10th 12.0 +0.3 6.3 21st 102.0 68.2 high 150%
Lancelin 26.6 +1.2 34.7 10th 15.9 +1.4 10.9 21st 29.0 31.0 average 94%
Medina Research Centre 26.2 +0.7 35.3 10th 14.3 +1.1 9.8 6th 57.0 40.3 high 141%
Pearce RAAF 27.3 +1.0 35.9 10th 13.4 +0.1 5.6 21st 50.0 35.0 high 143%
Perth Airport 26.4 +0.9 35.9 10th 14.0 +1.1 7.0 21st 53.4 41.4 average 129%
Perth Metro* 26.4 +0.7 35.4 10th 14.3 +0.7 9.2 21st 69.2 43.9 high 158%
Rottnest Island 24.6 +0.9 32.5 10th 18.0 +0.8 12.5 6th 35.8 36.5 average 98%
Swanbourne 26.1 +0.9 33.8 10th 15.8 +0.8 11.0 6th 85.4 39.5 v high 216%
South Coast (district 09A)
Albany 23.0 +2.2 34.0 10th 14.4 +1.7 9.0 7th 58.1 69.0 average 84%
Albany Airport 23.5   34.3 10th 12.3   5.0 7th 44.0
Bridgetown 23.9 +0.5 32.4 10th 10.2 +1.2 1.6 6th 31.2 51.7 average 60%
Bridgetown Comparison 24.3 +1.0 33.0 10th 10.3 +1.9 2.5 6th 35.2 46.2 average 76%
Bunbury 24.4 +0.3 30.7 10th 12.8 +1.2 6.1 6th 35.4 35.9 average 99%
Busselton Aero 24.3 +0.3 29.8 10th 11.9 +1.0 4.7 6th 22.6 35.3 average 64%
Cape Leeuwin 22.1 +0.8 26.9 26th 16.6 +1.2 11.9 24th 54.0 60.3 average 90%
Cape Naturaliste 23.4 +1.6 27.7 11th 15.3 +1.4 9.6 6th 37.6 43.9 average 86%
Collie East 24.0   31.8 10th 9.8   2.2 6th 34.0 49.5 average 69%
Donnybrook 24.7 +0.6 33.1 10th 12.6 +2.3 4.2 6th 50.2 49.7 average 101%
Dwellingup 23.2 +0.8 31.8 10th 11.2 +1.0 6.0 7th 88.2 67.2 average 131%
Esperance 24.8 +1.6 31.7 16th 13.8 +0.6 8.0 7th 27.6 46.1 average 60%
Esperance Aero 25.3 +2.1 31.5 16th 12.9 +0.2 7.3 6th 18.2 40.6 low 45%
Harvey 24.8 +0.1 33.2 10th 12.6 +0.4 6.5 6th 40.4 52.0 average 78%
Hopetoun North 24.8 +1.3 33.9 11th 13.4 +0.8 6.8 7th 25.6 40.6 low 63%
Jarrahwood 24.5 +0.8 32.0 10th 9.9 +1.4 2.0 23rd 43.8 48.4 average 90%
Mandurah 24.3 +0.5 31.7 10th 16.6 +1.1 11.2 6th 38.0 45.0 average 84%
Manjimup 22.8 +1.8 32.2 10th 12.0 +1.3 6.3 6th 33.2 60.3 low 55%
North Walpole 22.1   32.1 10th 13.3   7.1 7th 78.6
Pemberton 22.5 +1.4 32.1 10th 12.5 +1.6 7.0 6th 62.6 75.3 average 83%
Rocky Gully 22.9 +0.9 32.5 10th 11.8 +1.0 3.6 7th 27.0 52.0 average 52%
Windy Harbour 22.0 0.0 25.6 11th     5.6 7th 66.9 71.5 average 94%
Witchcliffe 23.0 +0.5 30.6 10th 12.6 +1.8 4.7 7th 132.0 70.5 high 187%
North Central (district 10)
Bencubbin 27.2 +1.4 33.8 9th 13.6 +0.9 6.4 21st 5.4 22.6 low 24%
Cunderdin Airfield 27.9 +1.5 34.4 10th 11.5 -0.4 5.7 21st 1.6 23.7 v low 7%
Kellerberrin 28.1 +2.5 34.0 9th 11.4 -0.3 4.5 24th 30.5 21.4 high 143%
Merredin 27.7 +2.3 34.0 10th 12.9 +0.2 4.6 21st 7.6 23.0 low 33%
Northam                 6.2 23.2 low 27%
York 27.5 +1.3 34.5 11th 10.1 -0.7 2.5 21st 11.3 19.3 average 59%
South Central (district 10A)
Beverley 27.6 +1.6 35.0 11th 11.6 +0.4 5.4 21st 19.4 23.1 average 84%
Brookton 25.5 +0.6 32.6 12th 11.3 +0.2 3.9 21st 8.8 25.9 low 34%
Corrigin 26.4 +2.3 32.8 9th 11.1 0.0 5.0 6th 2.6 22.6 v low 12%
Hyden 27.6 +2.1 34.8 9th 11.6 +0.5 3.1 23rd 1.7 23.6 v low 7%
Katanning 23.9 +0.6 32.5 11th 11.6 +0.7 4.8 24th 13.4 33.0 low 41%
Katanning Comparison 24.0 +1.2 32.6 10th 11.0 +0.7 4.2 23rd 14.2 30.8 low 46%
Lake Grace 25.4 +1.2 33.2 9th 12.5 +0.8 6.4 23rd 1.2 24.2 v low 5%
Lake Grace Comparison 25.7 +1.9 33.4 9th 12.1 +0.6 6.7 23rd 0.8 23.1 v low 3%
Narembeen 27.4 +1.6 34.0 9th 12.0 +0.1 5.9 23rd 7.5 22.9 low 33%
Narrogin 24.5 +1.5 32.2 10th 11.5 +1.1 4.5 6th 8.4 29.6 low 28%
Newdegate Research Station 25.8 +1.7 33.5 9th 9.5 -0.7 2.9 24th 3.0 26.6 low 11%
Ongerup 24.3 +1.6 32.6 9th 12.1 +1.0 7.0 19th 10.8 26.4 low 41%
Pingelly 25.5 +1.6 33.0 10th 12.0 +0.3 5.0 21st 6.2 27.2 low 23%
Ravensthorpe 25.6 +1.9 31.6 12th 12.9 +1.2 6.4 25th 6.3 33.2 v low 19%
Wagin 24.6 +0.9 32.7 10th 11.0 +0.4 4.5 6th 7.1 28.9 low 25%
Wandering 25.1 +0.6 33.3 10th 9.6 +0.3 3.0 21st 34.6 32.0 average 108%
Eucla (district 11)
Balladonia 26.8 +1.9 34.4 17th 10.9 0.0 6.2 7th 5.0 19.8 low 25%
Eucla 26.4 +2.8 37.7 5th 13.5 +0.2 8.2 26th 9.2 26.4 low 35%
Eyre 26.6 +2.6 38.3 17th 9.9 -2.0 -0.1 25th 2.8 25.0 low 11%
Forrest 28.4 +2.3 37.5 1st 11.1 -0.8 5.1 12th 1.4 19.4 low 7%
Red Rocks Point 25.2   36.1 17th 14.1   9.2 26th 3.6
South East (district 12)
Bulga Downs 28.9   34.3 1st 12.1   8.0 27th 0 21.1 lowest 0%
Kalgoorlie-Boulder Airport 26.8 +1.6 32.8 17th 12.6 0.0 6.6 24th 0.8 20.7 v low 4%
Laverton Aero 28.4 +1.9 35.5 1st 14.1 -0.8 8.1 22nd 1.0 18.4 v low 5%
Leonora 28.4 +0.5 34.4 1st 13.5 -1.3 8.7 25th 4.8 20.4 average 24%
Leonora Aero 28.3   34.6 1st 13.6   8.8 25th 3.6
Munglinup West 25.5   32.0 12th 12.2   7.1 24th 6.2 35.3 v low 18%
Norseman 27.2 +2.6 34.2 16th 12.3 +0.7 3.5 24th 1.5 23.4 low 6%
Norseman Aero 26.4 +1.2 33.8 16th 10.7 -0.1 1.9 23rd 0 27.4 v low 0%
Salmon Gums Res.Stn. 26.0 +2.3 34.0 16th 9.5 -0.4 1.0 24th 3.2 27.3 v low 12%
Southern Cross Airfield 27.2 +1.1 33.4 16th 10.7 -0.7 5.0 22nd 0.2 24.7 v low 1%
Yeelirrie 29.5 +0.7 35.0 4th 12.4 -1.6 6.0 13th 21.1 24.8 average 85%
North East (district 13)
Carnegie 31.5 +1.5 38.3 1st 15.4 -0.8 8.9 13th 4.1 23.3 average 18%
Giles Meteorological Office 29.3 -0.1 38.3 1st 16.2 -0.3 7.2 26th 7.8 15.8 average 49%
Telfer Aero 34.9 +0.4 39.7 3rd 20.0 -0.6 11.9 28th 3.8 20.0 average 19%
Warburton Airfield 30.6 +1.3 39.3 1st 15.3 +0.2 8.4 13th 1.8 18.3 average 10%
Wiluna 29.9 +0.7 35.0 4th 14.4 -0.7 7.0 22nd 11.0 29.0 average 38%
Offshore Islands (district 200)
Christmas Island Aero 27.7 -0.5 28.3 24th 23.7 +0.2 22.2 16th 134.6 219.6 average 61%
Cocos Island Airport 30.1 +0.4 30.9 8th 25.5 +0.3 23.4 13th 175.4 255.8 average 69%
Varanus Island 31.6 +0.5 33.8 4th 26.3 +0.3 24.3 30th 1.6 47.3 average 3%

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 11 am on Tuesday 1 May 2012. 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.

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.

Records in this summary are based on sites with at least 30 years of data.

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

Further information

Media
(03) 9669 4057
Enquiries