Tuesday, 4 March 2008 - Seasonal Climate Summary for Perth - Product Code: IDCKGC21L0

Hottest summer for thirty years in Perth

Mean daily maximum temperature - above average: The mean daily maximum temperature for Perth this summer was 31.0°C, which was the highest mean daily maximum temperature for Perth in summer since 1977/78, then 32.0°C which was Perth's hottest summer on record. The average for summer is 30.1°C.  Last summer the mean daily maximum temperature was 29.9°C. Daily values this summer ranged from a cool 20.1°C on 6 December 2007 to a very hot 44.2°C on 26 December 2007 (Boxing Day).

Perth's top 10 mean maximum temperatures
for summer (1897- 2008)
Year/s
Mean Maximum Temperatures (°C)
Departure from normal
Ranking
1977/78
32.0
+1.9
1
1931/32
31.4
+1.3
2
1961/62
31.3
+1.2
3
1960/61
31.0
+0.9
4
2007/08
31.0
+0.9
4
1999/00
30.9
+0.8
6
1994/95
30.9
+0.8
6
1995/96
30.9
+0.8
6
1997/98
30.8
+0.7
9
1975/76
30.7
+0.6
10
1979/80
30.7
+0.6
10

Days of 35°C and higherabove average: A daily maximum temperature of 35°C or higher was reached on 25 occasions this summer, whereas the average for summer is 16 such days. This was the greatest number of days of 35°C or higher since the 31 days in the summer of 1977/78. Between the dates 1st and 6th February 2008, Perth experienced six consecutive days with maximum temperatures greater than 35°C. This was the longest hot spell in Perth since the seven days between 31st December 1999 to 6th January 2000.

Mean daily minimum temperature - near average: The mean daily minimum temperature for Perth this summer was 17.8°C, compared to the average of 17.2°C. Daily minima ranged from a cool 7.9°C on 7 December 2007 to a warm 24.9°C on 14 February 2008. Last summer the mean daily minimum temperature was 16.9°C.

Rainfall - above average: This summer the rainfall in Perth was above average. From December to February, Perth received 65.6 mm over 9 days compared with the average of 35 mm on about 8 days. It was Perth's wettest summer since 1999/2000, then 146.2 mm on 13 days. Last summer, Perth recorded 27.8 mm over 11 days. Rainfall totals for individual months this summer were: December 18.0 mm (average 13 mm), January 0.0 mm (average 10 mm) and February 47.6 mm (average 12 mm). The wettest day was 8 February 2008 when 30.4 mm of rain was recorded.

Summer mean temperature and sunshine
Element

Summer 2007/08

Long- term Average

Highest

Year

Lowest

Year Records Commence
Maximum
Temperature (°C)
31.0
30.1
32.0
1977/78
26.5
1901/02
1897
Minimum Temperature (°C)
17.8
17.2
20.3
1977/78
15.4
1901/02
1897
Sunshine
(hours per day)
10.9
11.4
12.1
1997/98
8.7
1922/23
1898
Summer rainfall and rain days
Element Summer 2007/08 Long-term Average Highest Year Lowest Year Records Commence
Rainfall (mm)
65.6
35
180.4
1954/55
0.8
1974/75
1876
Rain days
9
8.5
20
1913/14
2
3 years
1876

Summer daily extremes
Element Summer 2007/08 Date Extreme Date

Records Commence

Highest daily maximum (°C)
44.2
26/12/2007
46.2
23/02/1991
1897
Lowest daily maximum (°C)
20.1
06/12/2007
14.9
17/12/1952
1897
Highest daily minimum (°C)
24.9
14/02/2008
29.3
* 3 years
1897
Lowest daily minimum (°C)
7.9
07/12/2007
8.4
02/12/2002
1897
Wettest 24 hours to 9am (mm)
30.4
08/02/2008
120.6
09/02/1992
1876

* Denotes highest February minimum temperature on record has occurred on the following dates: 6 February 1898, 8 February 1933 and 3 February 1962.

Past summers in Perth 1994/95−2007/08
Season
Mean Maximum (°C)
Mean Minimum (°C)
Total Rainfall (mm)
Rain Days
Mean Sunshine (hours per day)
1994/95
30.9
18.1
12.0
3
11.7
1995/96
30.9
17.4
6.2
5
11.6
1996/97
30.2
17.7
24.8
11
11.5
1997/98
30.8
17.3
1.8
2
12.1
1998/99
30.4
17.8
60.8
9
11.6
1999/00
30.9
18.3
146.2
13
11.1
2000/01
29.9
17.3
9.8
8
11.3
2001/02
29.3
16.3
31.4
10
11.4
2002/03
30.6
17.5
16.2
12
11.4
2003/04
30.4
17.5
7.6
6
11.6
2004/05
30.0
16.7
5.6
6
11.6
2005/06
28.0
16.2
54.0
14
10.6
2006/07
29.9
16.9
27.8
11
11.0
2007/08
31.0
17.8
65.6
9
10.9

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 (Mount 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 (Mount 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), or Glenn Cook tel: (08) 9263 2222 on weekdays.