Monday, 5 January 2009 - Monthly Climate Summary for Western Australia - Product code IDCKGC11R0

Western Australia in December 2008
A mostly cool wet month for WA

Summary

  • Above average rainfall for WA.
  • Below average mean maximum temperature for WA
  • Near average mean minimum temperature for WA.

Details

Rainfall

December rainfall in WA was above to very much above average in most of the Kimberley, Pilbara, Interior, Eucla, and southern parts of the Southwest Land Division (SWLD) and neighbouring southern Goldfields, with record high monthly totals reported in the northeast Kimberley. This contrasts with below to very much below average rainfall mainly in small areas of the Gascoyne (see December rainfall decile map). Averaged across WA as a whole, December 2008 was above average.

Tropical Cyclone Billy produced heavy rainfall and some flooding through the north Kimberley as it crossed the Kimberley coast near Wyndham early on the 20th, weakened to a tropical low and tracked across the north Kimberley, then crossed the coast near Kuri Bay on the 22nd to reform into a tropical cyclone again as it moved off into the Indian Ocean and eventually dissipated. Wyndham received 254.0 mm to 9am on the 21st, its highest daily rainfall on record for December, and the highest daily rainfall recorded in WA for 2008.

Maximum temperature

Mean maximum temperatures were below to very much below average across eastern and southern WA, with up to 3°C cooler than normal maxima in the South Coastal district and the central eastern Interior. Averaged across the state, the mean maximum temperature was 0.9ºC below average. (see December maximum temperature anomaly map).

Minimum temperature

Mean minimum temperatures were below to very much below average in the north and east Kimberley, and the west Gascoyne and neighboring areas, with up to 2°C cooler than normal mean minima in the east Kimberley. Conversely, minima were above average in the far west Kimberley, and Eucla and adjacent parts, with mean minima in the Eucla up to 2ºC above normal. Averaged across the state as a whole, the WA mean minimum temperature was close to average. (see December minimum temperature anomaly map).

Further information

Western Australia Climate Services Centre
Bureau of Meteorology
Phone (08) 9263 2222
Email climate.wa@bom.gov.au

Extremes

Hottest day
Highest temperature
45.7 °C at Marble Bar on the 19th
Warmest days on average
Highest mean daily maximum temperature
40.9 °C at Marble Bar
Coolest days on average
Lowest mean daily maximum temperature
20.7 °C at Albany
Coldest day
Lowest daily maximum temperature
16.2 °C at Jacup on the 10th
Coldest night
Lowest temperature
3.9 °C at Eyre on the 7th
Coolest nights on average
Lowest mean daily minimum temperature
9.2 °C at Jarrahwood
Warmest nights on average
Highest mean daily minimum temperature
27.0 °C at Troughton Island
Warmest night
Highest daily minimum temperature
32.0 °C at Wittenoom on the 19th
Wettest overall
Highest total rainfall

697.8 mm at Oombulgurri

Wettest day
Highest daily rainfall
254.0 mm at Wyndham on the 21st
Highest wind gust
94 km/h at Giles Meteorological Office on the 11th

Records

Record highest December daily rainfall
Highest daily rainfall
in December 2008 (mm)
Previous highest
for December
Years of
record
Gnowangerup 48.0 on the 10th 46.7 on the 31st in 1959 95
Fossil Downs 160.0 on the 26th 114.3 on the 10th in 1916 93
Bremer Bay 59.0 on the 11th 47.8 on the 20th in 1913 77
Pemberton 56.9 on the 21st 46.7 on the 12th in 1996 68
Oombulgurri 223.0 on the 20th 147.3 on the 4th in 1948 49
Derby Aero 126.8 on the 23rd 102.0 on the 15th in 1996 48
Wyndham 254.0 on the 21st 154.8 on the 12th in 1998 41
Yalleen 61.4 on the 30th 51.8 on the 19th in 1994 41
Esperance Aero 29.0 on the 11th 25.6 on the 1st in 1999 39



Record highest total December rainfall
Total rainfall
for December 2008 (mm)
Previous highest
for December
Years of
record
Average for
December
Peppermint Grove 119.0 110.3 in 1983 101 23.9
Fossil Downs 284.3 253.6 in 1917 99 82.8
Bremer Bay 112.8 105.4 in 1983 98 23.1
Northcliffe 105.2 90.7 in 1944 83 35.3
Kimberley Res.Station 480.3 322.8 in 1987 64 144.0
Oombulgurri 697.8 359.3 in 1933 56 133.8
Chesalon 80.0 72.0 in 1987 43 21.3
Wyndham 676.6 311.5 in 1996 41 148.9
Cherrabun 208.0 129.6 in 1971 37 51.7
Kununurra Aero 382.0 333.2 in 1996 34 134.4
Mount Elizabeth 503.1 354.1 in 1998 34 169.8
Brooking Springs 299.4 278.0 in 1996 32 97.5




Record lowest December daily maximum temperature
Lowest daily maximum
temperature
in December 2008 (°C)
Previous lowest
for December
Years of
record
Average for
December
Wyndham 26.0 on the 19th 26.5 on the 4th in 2000 41 38.2




Record lowest December temperature
Lowest temperature
in December 2008 (°C)
Previous lowest
for December
Years of
record
Average for
December
Mandora 14.5 on the 13th 16.4 on the 5th in 1978 44 24.3
Learmonth Airport 14.2 on the 11th 14.4 on the 1st in 1981 34 20.7





Notes

This statement has been prepared based on information available at 1 pm on Monday 5 January 2009. 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 30 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

Further information

Western Australia Climate Services Centre
Bureau of Meteorology
Phone (08) 9263 2222
Email climate.wa@bom.gov.au