Tuesday, 2 June 2009 - Seasonal Climate Summary for Perth - Product Code: IDCKGC21L0

Second driest and warmest autumn for Perth with record sunshine

Rainfall - second driest on record: In autumn 2009, Perth received 57.8 mm on 12 days, compared with the average of 181 mm on about 24 days. This was the second driest autumn on record since records commenced in 1876, and was the driest autumn since the record low of 42.4 mm on 19 days in 1983.  Rainfall totals for individual months this autumn were: March 6.8 mm (average 19 mm), April 5.0 mm (average 44 mm) and May 46.0 mm (average 118 mm). The wettest day was on 23 May 2009 when 21.0 mm of rain was recorded. Last autumn, Perth recorded 227.4 mm on 29 days.

Perth's top ten driest autumns
Year
Rainfall (mm)
Rain days
Ranking
1983
42.4
19
1
2009
57.8
12
2
2006
61.0
19
3
1972
63.7
19
4
1914
66.8
25
5
1912
73.7
15
6
1959
79.3
26
7
1895
80.3
20
8
2000
81.3
16
9
1940
82.6
18
10

Mean daily maximum temperature - second highest on record: The mean daily maximum temperature for Perth this autumn was 26.9°C, compared to the average of 25.7°C. This was the second highest mean daily maximum temperature for autumn since records commenced in 1897, and was the warmest autumn since the record high of 27.2°C in 1978. Daily values this autumn ranged from a cool 16.1°C on 23 May to a very hot 39.8°C on 15 March.  Last autumn the mean daily maximum temperature was 25.4°C.

Perth's top 10 mean maximum temperatures
for autumn
Year
Mean Maximum Temperatures (°C)
Departure from normal
Ranking
1978
27.2
+1.5
1
2009
26.9
+1.2
2
1994
26.6
+0.9
3
2003
26.6
+0.9
3
1988
26.5
+0.8
5
1976
26.4
+0.7
6
1983
26.4
+0.7
6
1998
26.4
+0.7
6
1972
26.2
+0.5
9
2005
26.2
+0.5
9

Mean daily minimum temperature - below average: The mean daily minimum temperature for Perth this autumn was 12.5°C, compared to the average of 13.6°C. Daily minima ranged from a cold 3.3°C on 25 May to a warm 21.7°C on 1 March. Last autumn the mean daily minimum temperature was 13.2°C.

Mean daily sunshine hours - highest on record: Perth's mean daily sunshine hours this autumn was 9.0 hours, compared with the average of 8.1 hours. This was the highest mean daily sunshine hours for autumn since sunshine records commenced in Perth in 1898. The previous record was 8.8 hours in 1972.

Autumn mean temperature and sunshine
Element

Autumn 2009

Long- term Average

Highest

Year

Lowest

Year Records Commence
Maximum
Temperature (°C)
26.9
25.7
27.2
1978
22.3
1917
1897
Minimum Temperature (°C)
12.5
13.6
16.6
1988
12.1
1960
1897
Sunshine
(hours per day)
9.0
8.1
8.8
1972
6.0
1926
1898
Autumn rainfall and rain days
Element Autumn 2009 Long-term Average Highest Year Lowest Year Records Commence
Rainfall (mm)
57.8
181
372.4
1879
42.4
1983
1876
Rain days
12
23.6
42
1926
10
1886
1876

Past autumns in Perth 1994−2009
Season
Mean Maximum (°C)
Mean Minimum (°C)
Total Rainfall (mm)
Rain Days
Mean Sunshine (hours)
1994
26.6
13.8
101.4
16
8.7
1995
25.6
13.1
169.4
22
8.3
1996
25.6
13.1
86.8
23
8.2
1997
24.6
14.1
175.0
27
7.5
1998
26.4
14.4
151.6
28
7.8
1999
26.0
14.8
158.4
25
7.8
2000
25.6
13.0
81.2
16
8.5
2001
25.7
13.3
118.8
21
8.2
2002
25.6
13.7
169.0
33
8.1
2003
26.6
14.6
203.0
28
8.0
2004
25.7
13.1
115.2
18
8.5
2005
26.2
14.9
271.2
32
7.2
2006
25.3
12.4
61.0
19
8.6
2007
25.5
12.9
144.0
24
8.6
2008
25.4
13.2
227.4
29
8.5
2009
26.9
12.5
57.8
12
9.0

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 Perth (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 Perth (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) and Glenn Cook
Western Australia Climate Services Centre
on, tel: (08) 9263 2222, office hours.