Friday 31 May 2002

SEASONAL CLIMATE SUMMARY - WESTERN AUSTRALIAN REGIONAL OFFICE

Autumn weather in Perth about average

Rainfall: Autumn rainfall was slightly below average this year, while rain days were slightly above average. Perth received 169.0 millimetres of rain over 33 days compared with the average of 188mm over 26 days. The last time the Perth metropolitan site recorded above-average rainfall in autumn was in 1990, when 235.4mm fell. Last autumn, 118.8mm was recorded. Historically, autumn rainfall has ranged from a low of 42.4mm in 1983 to 372.4mm in 1879. The wettest day this autumn was 17 April when 69.6mm was recorded, which was the wettest April day on record. The rainfall for each autumn month was: March 2.6mm (average 19mm), April 96.0mm (average 46mm) and May 70.4mm (average 123 mm).

Maximum temperatures: The mean daily maximum temperature in Perth this autumn of 25.6 degrees Celsius was about average. The average is about 25 degrees. The mean maximum temperature last autumn was also 25.6 degrees. Daily maxima this autumn ranged from a mild 18.6 degrees on 11 May to a hot 36.4 degrees on 12 March.

Minimum temperatures: Perth's mean daily minimum temperature in autumn of 13.6 degrees was about average. The long-term average is about 13 degrees. Daily minima ranged from a cold 4.5 degrees on 22 May to a warm 21.6 degrees on 15 March.

Temperature and sunshine averages
Element Autumn
2002		 Average Highest
average		 Year Lowest
average		 Year Years of
record
Maximum temp (°C) 25.6 25 27.2 1978 22.3 1917 106
Minimum temp (°C) 13.6 13 16.6 1988 12.1 1960 106
Sunshine (hours/day) 8.1 8.1 8.8 1972 6.0 1926 105
Rainfall averages and extremes
Element Autumn 2002 Average Highest Year Lowest Year Years of
record
Rainfall (mm) 169.0 188 372.4 1879 42.4 1983 127
Rain days 33 26 42 1926 10 1886 127

Daily extremes
Element Autumn 2002 Date Extreme Date Years of
record
Highest daily maximum (°C) 36.4 12 March 42.3 5/3/1990 106
Lowest daily maximum (°C) 18.6 11 May 11.5 23/5/1995 106
Lowest daily minimum (°C) 4.5 22 May 1.3 11/5/1914 106
Highest daily minimum (°C) 21.6 15 March 28.3 2/3/1934 106
Wettest 24-hour period (mm) 69.6 17 April 77.0 9/3/1934 123

Note: Official Perth observations have been recorded at several different sites over the years. Changes in site location can affect both temperature and rainfall readings. Due to a relatively short period of record for the current site, temperature averages have been estimated to represent that site.

Ends

Further information:
John Relf (JR), or Glenn Cook, tel:(08) 9263 2222 or, after hours, the senior forecaster.