Friday 31 May 2002

MONTHLY CLIMATE SUMMARY - WESTERN AUSTRALIAN REGIONAL OFFICE

May drier and warmer than normal in Perth

Rainfall: May rainfall in Perth was below average this year. The city received 70.4 millimetres of rain over 16 days compared with the average of 123mm over 14 days. Last May, 108.6mm was recorded. The last time rainfall exceeded the May mean total was in 1995. Historically, May rainfall has ranged from a low of 14.1mm in 1964 to 308.1mm in 1879. The wettest day this month was on the 6th when 20.8mm was recorded.

Maximum temperatures: The mean daily maximum temperature for Perth in May of 22.9 degrees Celsius was above average. The average is about 21 degrees. Daily maxima ranged from a mild 18.6 degrees on the 11th to a hot 34.3 degrees on the 1st, the highest May maximum temperature on record. The previous record of 32.4 degrees was on 2 May 1907. Also, the maximum of 26.7 degrees recorded on 31 May was the warmest last day of autumn on record for the Perth metropolitan site.

Minimum temperatures: The mean daily minimum temperature for Perth in May of 11.2 degrees was above average. The long-term average is about 10 degrees. Daily minima ranged from a cold 4.5 degrees on the 22nd to a warm 19.2 degrees on the 3rd.

May averages
Element May 2002 Average Highest
average
Year Lowest
average
Year Years of
record
Maximum temp (°C) 22.9 21 23.9 1972 18.7 1931,56 106
Minimum temp (°C) 11.2 10 13.8 1972 8.8 2000 106
Sunshine (hours/day) 7.0 6.6 7.9 2000 3.4 1905 105
May rainfall averages and extremes
Element May 2002 Average Highest Year Lowest Year Years of
record
Rainfall (mm) 70.4 123 308.1 1897 14.1 1964 127
Rain days 16 14 25 1921 5 1913 127

May daily extremes
Element May 2002 Date Extreme Date Years of
record
Highest daily maximum (°C) 34.3 1st 34.3 1/5/2002 106
Lowest daily maximum (°C) 18.6 11th 11.5 23/5/1995 106
Lowest daily minimum (°C) 4.5 22nd 1.3 11/5/1914 106
Highest daily minimum (°C) 19.2 3rd 20.8 1/5/1983 106
Wettest 24-hour period (mm) 20.8 6th 76.2 17/5/1942 123

Climate of Perth in June

June is Perth's wettest month of the year, on average. Cool and cloudy days are common. Some are cold, windy and showery, while others are sunny with light winds. Perth experienced its wettest month on record in June 1945 when 476.1mm of rain fell over 23 days. Perth also recorded its record fewest hours of sunshine in that month, with an average of only 2.9 hours a day.

June averages
Element Average Highest
average
Year Lowest
average
Year Years of
record
Maximum temperature (°C) 19 20.6 1983 15.9 1898 105
Minimum temperature (°C) 9 12.6 1964 7.1 1931 105
Sunshine (hours/day) 5.8 6.9 1955 2.9 1945 104
June rainfall and rain days
Element Average Highest Year Lowest Year Years of
record
Rainfall (mm) 182 476.1 1945 54.9 1877 126
Rain days 17 27 1918,70 9 1893,1976 126

June daily extremes
Element Highest Date Lowest Date Years of
record
Maximum temperature (°C) 28.1 5/6/1975 8.8 26/6/1956 105
Minimum temperature (°C) 18.7 12/6/1988 1.3 11/6/1995 105
Rainfall (mm) 24 hours to 9am 99.1 10/6/1920 - - 122

Warm days in June: On average, Perth can expect about seven days when the maximum temperature is 20 degrees or more. The greatest number of such days in June was 21 days in 1983. Last June, Perth recorded 18 such days.

Cold days in June: On average, Perth can expect about two days when the maximum temperature is 15 degrees or less. The greatest number of such days in June was 10 in 1931 and 1955. Last June, Perth recorded two such days.

June top 10 hottest June top 10 coolest
Position Date Max
temp°C
Position Date Max
temp°C
1 5 June 1975 28.1 1 26 June 1956 08.8
2 02 June 1914 27.6 2 8 June 1923 10.0
3 3 June 1984 26.9 3 24 June 1966 10.2
4 4 June 1984 26.8 4 18 June 1931 10.4
5 2 June 1977 26.3 5 25 June 1956 10.6
6 4 June 1919 26.2 6 29 June 1920 10.9
6 11 June 1972 26.2 7 26 June 1946 11.0
8 12 June 1925 25.7 8 13 June 1898 11.6
8 12 June 2000 25.7 9 18 June 1936 12.1
10 16 June 1935 25.6 9 30 June 1950 12.1
10 28 June 1985 25.6 9 20 June 1955 12.1
10 24 June 1988 25.6 9 9 June 1973 12.1

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.