Cold finish to May in Perth

Tuesday 1 Jule, 2004

MONTHLY CLIMATE SUMMARY - WESTERN AUSTRALIAN REGIONAL OFFICE

Cold finish to May in Perth

Mean daily maximum temperature below average: Perth's mean daily maximum temperature in May was 21.3 degrees Celsius, compared with the average of 22.4 degrees. The lowest daily maximum was a cold 13.0 degrees on the 31st, which was the lowest May maximum temperature since the 11.5 degrees on 23 May 1995. The highest daily maximum temperature was a warm 30.5 degrees on the 6th.

Mean daily minimum temperature below average: Perth's mean daily minimum temperature in May was 9.7 degrees, compared with the average of 10.9 degrees. Daily minima for the month ranged from a cold 2.4 degrees on the 27th, which was the lowest May minimum temperature for eight years, to a mild 17.0 degrees on the 6th.

The official Perth observation site at Mount Lawley recorded its greatest number of cold nights on record for May with 9 nights of minimum temperature 5 degrees or less. The previous record of 5 nights occurred in 1996. Observations at Mount Lawley commenced in November 1993.

Rainfall near average: The city received 103.2 millimetres of rainfall over 12 days, compared with the average of 119 mm over 12 days. Last May Perth registered 92.6 millimetres of rain over 13 days. The last time rainfall exceeded the May mean was in 1995 with 138.6 mm. Historically, May rainfall has ranged from 14.1 mm in 1964 to 308.1 mm in 1879. Total rainfall for January to May this year was 117.2 mm, making it the driest start to the year since the 90.0 mm in 1996. The driest January to May period on record was 64.3 mm in 1972, whilst the average rainfall for this period is 206 mm.

Mean daily sunshine hours near average: Perth's mean daily sunshine hours in May was 7.0 hours which was close to the average of 6.7 hours.

May monthly mean temperature and sunshine
Element

2004

 Long-term Average†

Highest

 Year

Lowest

 Year Records Commence
Maximum
Temperature (°C)
21.3
22.4
24.0
2003
18.7
1931/56
1897
Minimum
Temperature (°C)
9.7
10.9
13.8
1972
8.8
2000
1897
Sunshine
(hours/day)
7.0
6.7
7.9
2000
4.4
1905
1898
May monthly rainfall and rain days
Element 2004 Long-term Average† Highest Year Lowest Year Records Commence
Rainfall (mm)
103.2
119
308.1
1879
14.1
1964
1876
Rain days
12
12
25
1921
5
1913
1876

May daily extremes
Element 2004 Date Extreme Date

Records Commence
Highest daily maximum (°C)
30.5
06/05/2004
34.3
01/05/2002
1897
Lowest daily maximum (°C)
13.0
31/05/2004
11.5
23/05/1995
1897
Highest daily minimum (°C)
17.0
06/05/2004
20.8
01/05/1983
1897
Lowest daily minimum (°C)
2.4
27/05/2004
1.3
11/05/1914
1897
Wettest 24 hours to 9am (mm)
33.4
10/05/2004
76.2
17/05/1942
1876

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 monthly mean temperatures and sunshine
Element Average Highest Year Lowest Year

Records
Commence
Maximum temperature (°C)
19.2
20.6
1983
15.9
1898
1897
Minimum temperature (°C)
8.7
12.8
1964
6.9
2001
1897

Sunshine
(hours/day)
5.8
7.3
2001
2.9
1945
1898
June monthly rainfall and rain days
Element
Average
Highest
Year
Lowest
Year
Records Commence
Rainfall (mm)
179
476.1
1945
54.9
1877
1876
Rain days
16
27
1918/70
9
1893/1976
1876

June daily extremes
Element
Highest
Date
Lowest
Date
Records Commence
Maximum temperature (°C)
28.1
05/06/1975
8.8
26/06/1956
1897
Minimum temperature (°C)
18.7
12/06/1988
1.2
19/06/2003
1897
Rainfall 24 hours to 9am (mm)
99.1
10/06/1920
n/a
n/a
1880

Warm days in June: On average, Perth can expect ten 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 eleven such days.

Cold days in June: On average, Perth can expect one day 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 1 such day.

Cold nights in June: Perth has a mean of 6 cold nights when the minimum temperature is 5 degrees or lower. The greatest number of such nights was in 2001 with twelve. Last June, Perth recorded 11 such nights

June top 10 hottest
June top 10 coolest
Position
Date
Max temp (°C)
Position
Date
Max temp (°C)
1
05 June 1975
28.1
1
26 June 1956
8.8
2
02 June 1914
27.6
2
08 June 1923
10.0
3
03 June 1984
26.9
3
24 June 1966
10.2
4
04 June 1984
26.8
4
18 June 1931
10.4
5
02 June 1977
26.3
5
25 June 1956
10.6
6
04 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
09 June 1973
12.1

†Note: Official Perth observations have been recorded at several different sites with varying instrumentation over the years, and these changes can affect the continuity of the climate record. For the current Mt Lawley site, the most significant changes of this kind relate to temperature and rain days. For that reason, current mean temperature and rain-day data quoted here are based only on readings from the Mt Lawley site, which commenced observations in 1993. Sunshine recordings are from Perth Airport and for similar reasons current means use only Perth Airport data, which commenced in 1993.

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

© 2004 Bureau of Meteorology Perth Western Australia