Thursday, 2 October 2008 - Monthly Climate Summary for Western Australia - Product code IDCKGC11R0

Western Australia in September 2008

A Warm September for Most of WA

Summary

  • Very much above average minimum temperatures for WA.
  • Above average maximum temperatures for WA.
  • Near average rainfall for the state.

Archives of previous monthly summaries for Western Australia are also available, as are summaries for other states and many other climate summaries and diagnostics, in particular the new online version of the Monthly Weather Review.

Details

Rainfall

September rainfall in WA was a mixture of well above and below average. While the Kimberley, northern Interior, parts of the Pilbara and northern Gascoyne, eastern parts of the South West Land Division and southwest Goldfields all experienced above to very much above average rainfall, southeast areas of the state and southern parts of the Gascoyne recorded below to very much below average rainfall totals for the month (see the September rainfall decile map). Averaged across WA as a whole, the rainfall for September was near average.

Early in the month, storm activity in the east Kimberley produced above average rainfall for the area. Mount Elizabeth recorded 47.0 mm on the 3rd, and 54.6 mm for the month, breaking both the daily and monthly September records. A slow moving cloud band progressed across the south of the state on the 25th, 26th and 27th and produced record September daily rainfall totals for several sites, particularly in the Central Wheat Belt and eastern Great Southern districts (see records below).

Temperature

Averaged across WA as a whole, September was above average for daily maximum and very much above average for daily minimum temperatures. Eastern and northern parts of the state were 1 to 3°C above normal in terms of daily maxima, while the in the west daily maxima was close to average (see maximum temperature anomaly map). Minimum temperatures were up to 3°C warmer than the long term mean in the north, while in the south overnight temperatures were generally close to average(see minimum temperature anomaly map).

Cool southerly winds in the wake of a cold front on the 21st caused low minimum temperatures and widespread frost in the south of the state on the morning of the 22nd, particularly in the Great Southern, with several stations recording record September daily minima (see records below). Pingelly recorded −1.6°C on the 22nd, breaking the previous September record for daily minimum of −1.1°C set on the 3rd in 1970 and also equalling the record for all months previously observed on 12 June 1891 and 12 July 2005.

Further information

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

Extremes

Hottest day
Highest temperature
41.3°C at Curtin Aero on the 21st
Warmest days on average
Highest mean daily maximum temperature
38.4°C at Curtin Aero
Coolest days on average
Lowest mean daily maximum temperature
16.1°C at Shannon
Coldest day
Lowest daily maximum temperature
9.4°C at Katanning Comparison on the 21st
Coldest night
Lowest temperature
−2.9°C at Wandering on the 22nd
Coolest nights on average
Lowest mean daily minimum temperature
4.8°C at Wandering
Warmest nights on average
Highest mean daily minimum temperature
24.7°C at Troughton Island
Warmest night
Highest daily minimum temperature
27.9°C at Wyndham on the 22nd
Wettest overall
Highest total rainfall
163.0 mm at Walpole
Wettest day
Highest daily rainfall
58.8 mm at Norseman on the 27th
Highest wind gust
117 km/h at Rottnest Island on the 21st

Records

Record highest September daily rainfall
Highest daily rainfall
in September 2008 (mm)
Previous highest
for September
Years of
record
Gingin 55.0 on the 26th 44.0 on the 11th in 1999 102
Norseman 58.8 on the 27th 30.6 on the 30th in 2003 102
Kellerberrin 26.2 on the 26th 23.6 on the 10th in 1913 101
Northam 33.6 on the 26th 31.2 on the 10th in 1973 101
Koorikin 32.4 on the 26th 29.2 on the 28th in 1948 97
Doodlakine 24.2 on the 26th 22.4 on the 20th in 1992 96
Bungulla 31.0 on the 26th 30.5 on the 21st in 1955 81
Hyden 32.0 on the 26th 28.2 on the 1st in 1952 79
Graham Rock 39.6 on the 26th 24.9 on the 30th in 1958 75
Bonnie Rock 26.0 on the 27th 25.4 on the 10th in 1968 73
Karlgarin 27.6 on the 26th 21.8 on the 22nd in 1958 72
Mordetta 31.4 on the 26th 20.0 on the 23rd in 1992 37
Mount Elizabeth 47.0 on the 3rd 29.2 on the 7th in 1974 36
Mount Howick 53.0 on the 27th 32.2 on the 21st in 1978 34



Record highest total September rainfall
Total rainfall
for September 2008 (mm)
Previous highest
for September
Years of
record
Normal for
September
Norseman 77.0 65.6 in 1997 111 21.2
Mount Elizabeth 54.6 51.2 in 1975 36 8.5

Highest total September rainfall for at least 30 years
Total rainfall
for September 2008 (mm)
Most recent higher
for September
Years since
higher
Normal for
September
Holt Rock 51.8 65.3 in 1959 49 26.1
Telina Downs 112.6 113.5 in 1964 41 56.3
Graham Rock 63.0 67.9 in 1970 38 28.4
Salmon Gums Res.Stn. 70.2 71.4 in 1970 37 31.8
Kondinin 59.4 85.4 in 1973 35 28.2
Amrista Park 55.6 56.2 in 1973 34 29.3
Bodallin South 59.9 67.8 in 1970 33 25.4
Xantippe 31.8 45.1 in 1973 33 17.2
Balgo Hills 20.2 75.4 in 1974 32 3.0



Record highest September daily minimum temperature
Highest daily minimum
temperature
in September 2008 (°C)
Previous highest
for September
Years of
record
Normal for
September
Brookton 14.0 on the 25th 13.5 on the 20th in 1972 42 5.2



Record lowest September temperature
Lowest temperature
in September 2008 (°C)
Previous lowest
for September
Years of
record
Normal for
September
Katanning Comparison −1.4 on the 22nd −1.2 on the 1st in 2005 103 6.3
Perth Metro 1.0 on the 22nd 1.5 on the 1st and 9th in 2005 110 9.5
Pingelly −1.6 on the 22nd −1.1 on the 3rd in 1970 38 6.3
Hyden −2.0 on the 22nd = −2.0 on the 23rd in 1998 37 5.7


Notes

This statement has been prepared based on information available at 10 am on Thursday 2 October 2008. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Normals 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 ("normal") rain.

Further information

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