Monday, 2 November 2009 - Monthly Climate Summary for Western Australia - Product code IDCKGC21R0

Western Australia in October 2009
A very dry and warm October


  • Very much below average rainfall for WA and 5th driest October for Southwest WA.
  • Above average mean maximum temperature for WA
  • Above average mean minimum temperature for WA.

An archive of previous monthly summaries for Western Australia is also available, as are summaries for other states and many other climate summaries and diagnostics.

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Details

Rainfall

Rainfall in October 2009 was below to very much below average for much of the Southwest Land Division (SWLD) and western Goldfields, as well as isolated patches in the north and east of the state. Many locations in the south and west of the SWLD received their lowest October rainfall since the very dry October 1969, and several towns had their driest October on record.

A series of troughs during October and early thunderstorm activity produced isolated moderate rainfall in the north, resulting in patches of above average rainfall in the southern Kimberley, eastern Pilbrara and parts of the Gascoyne (see October rainfall decile map). Averaged over the state as a whole, rainfall in October 2009 was very much below average, whilst it was the 5th driest October for the Lower Southwest (southwest of a line from Jurien to Bremer Bay).

Maximum temperature

October 2009 saw above to very much above average daytime temperatures over much of WA from the north and west Kimberley, through most of the Pilbara, Interior, inland Gascoyne, west and east SWLD, Goldfields and Eucla, with areas of up to 4°C warmer than normal in the northern Goldfields and southwest Interior (see October maximum temperature anomaly map). A few stations in the SWLD and Eucla recorded their hottest October day on record, and Yeelirrie in the northern Goldfields registered the hottest mean maximum temperature for October in its 31 years of record.

When averaged over the whole state, the mean maximum temperature for October was above average.

Minimum temperature

Mean minimum temperatures during October 2009 were above to very much above average over a large area of the Pilbara, Gascoyne, SWLD, Goldfields, western Interior and Eucla, with up to 3°C above average minima in the northern Goldfields and southern Interior. In contrast, below to very much below average mean minimum temperatures were observed in most of the Kimberley and adjacent northeast Interior, with mean minima to 4°C below average in the central Kimberley (see October minimum temperature anomaly map).

The first day of the month saw several locations scattered throughout WA record their lowest October temperature on record as a cold southerly airstream passed through the state, while in contrast, many locations observed their warmest October night on record during the last week of October as a heat trough and a very warm airmass moved slowly across the state.

The state averaged mean minimum temperature was in the above average range.

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		 45.6°C at Mandora on the 29th
Warmest days on average
Highest mean daily maximum temperature		 39.9°C at Fitzroy Crossing Aero
Coolest days on average
Lowest mean daily maximum temperature		 18.3°C at Albany
Coldest day
Lowest daily maximum temperature		 12.2°C at Manjimup on the 11th
Coldest night
Lowest temperature		 −2.6°C at Eyre on the 17th
Coolest nights on average
Lowest mean daily minimum temperature		 7.5°C at Wandering &York
Warmest nights on average
Highest mean daily minimum temperature		 26.9°C at Troughton Island
24.4°C at Kuri Bay &Truscott(mainland)
Warmest night
Highest daily minimum temperature		 31.4°C at Wittenoom on the 30th
Wettest overall
Highest total rainfall		 67.0 mm at Barrett Meadows
Wettest day
Highest daily rainfall		 45.0 mm at Kununurra Checkpoint on the 17th
Highest wind gust
 93 km/h at Forrest on the 10th

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Records

Record highest October daily rainfall
Highest daily rainfall
in October 2009 (mm) 		Previous highest
for October		 Years of
record
Fossil Downs 30.0 on the 6th 28.4 on the 25th in 1950 97
Amery Acres 29.0 on the 27th 19.8 on the 15th in 1975 46


Record lowest total October rainfall
Total rainfall
for October 2009 (mm) 		Previous lowest
for October		 Years of
record		 Average for
October
Bremer Bay 9.8 11.6 in 2004 101 54.4
Ferguson Valley 9.4 11.0 in 1992 38 55.0
Jarrahwood 11.2 12.7 in 1992 35 60.3

Lowest total October rainfall for at least 30 years
Total rainfall
for October 2009 (mm) 		Most recent lower
for October		 Years since
lower		 Average for
October
Bridgetown Comparison 9.0 3.1 in 1969 40 62.4
Cape Leeuwin 12.6 8.6 in 1969 40 65.8
Cape Naturaliste 11.8 4.6 in 1969 40 51.0
Greenbushes 11.7 2.8 in 1969 40 69.6
Lancelin 6.0 4.1 in 1969 40 29.7
Nannup 6.8 2.8 in 1969 40 71.7
Newbicup 8.8 2.0 in 1969 40 43.1
Pemberton 38.1 13.2 in 1969 40 90.9
Perth Airport 4.0 1.3 in 1969 40 44.8
Warner Glen 17.0 9.4 in 1969 40 68.8
Margaret River 22.3 9.0 in 1969 39 73.8
Jurien Bay 5.4 0.5 in 1969 38 25.6
Forest Grove 29.4 29.2 in 1972 37 75.7
Waroona 11.6 2.8 in 1969 36 57.6
Arthur River 8.5 0.3 in 1969 33 34.4


Record highest October temperature
Highest temperature
in October 2009 (°C) 		Previous highest
for October		 Years of
record		 Average for
October
Donnybrook 35.3 on the 17th 35.1 on the 31st in 1936 101 21.0
Lancelin 39.0 on the 17th 37.1 on the 26th in 1972 44 22.3
Balladonia 41.6 on the 28th 41.5 on the 26th in 1981 43 25.0


Record highest October mean daily maximum temperature
Mean daily maximum
temperature
for October 2009 (°C) 		Previous highest
for October		 Years of
record		 Average for
October
Yeelirrie 33.6 33.5 in 2004 35 29.8



Record highest October daily minimum temperature
Highest daily minimum
temperature
in October 2009 (°C) 		Previous highest
for October		 Years of
record		 Average for
October
Bridgetown Comparison 17.2 on the 27th 16.8 on the 17th in 2002 103 6.8
Kalgoorlie-Boulder Airport 25.7 on the 28th 24.1 on the 24th in 1990 69 11.0
Port Hedland Airport 28.3 on the 29th 26.3 on the 21st in 2006 62 18.3
Cape Naturaliste 18.6 on the 26th 18.3 on the 13th in 1991 53 11.0
Pemberton 17.4 on the 27th 17.0 on the 17th in 2002 52 8.6
Roebourne 29.4 on the 30th 28.8 on the 19th in 1994 52 19.6
Balladonia 20.9 on the 28th 19.7 on the 4th in 2005 43 8.8


Record lowest October temperature
Lowest temperature
in October 2009 (°C) 		Previous lowest
for October		 Years of
record		 Average for
October
Kellerberrin −1.5 on the 1st −1.0 on the 10th in 2005 97 8.8
Carnarvon Airport 8.1 on the 1st 8.8 on the 1st in 1973 64 16.3
Mardie 7.6 on the 1st 8.4 on the 6th in 1964 53 17.3
Emu Creek Station 8.4 on the 1st 8.7 on the 15th in 1980 38 16.7


Record highest October mean daily minimum temperature
Mean daily minimum
temperature
for October 2009 (°C) 		Previous highest
for October		 Years of
record		 Average for
October
Hyden 10.0 9.9 in 1991 37 8.1

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Notes

This statement has been prepared based on information available at 12 pm on Monday 2 November 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 5 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