Tuesday, 5 January 2010 - Annual Climate Summary for Perth - Product Code:IDCKGC51L0

Second warmest year on record for Perth

Annual mean maximum temperature - very much above average: Perth's annual mean maximum temperature in 2009 was 25.0°C, which is the second warmest year on record for Perth and the highest annual mean maximum temperature since the 25.2°C in 1978, the warmest ever year in Perth. The annual average is 24.4°C whilst last year the mean annual maximum temperature was 24.6°C.

Perth's top 10 warmest years
Year
Max°C
Depart
Rank
1978
25.2
+0.8
1
2009
25.0
+0.6
2
1972
24.9
+0.5
4
1988
24.8
+0.4
4
1999
24.8
+0.4
4
2006
24.8
+0.4
4
1994
24.7
+0.3
7
1976
24.6
+0.2
8
1977
24.6
+0.2
8
2008
24.6
+0.2
8

Daily maxima ranged from a cold 12.8°C on 23 June to a very hot 41.8°C on 16 January.

During 2009, Perth recorded 58 hot days when the maximum temperature was 32°C or higher, the greatest such number of days since the 66 days in 1978. The annual average is 47.

Annual mean minimum temperature - average: Perth's annual mean minimum temperature in 2009 was 12.7°C and equal to the average. Last year the mean annual minimum temperature was 12.3°C.

Daily minima ranged from a cold 1.5°C on 14 July to a warm 23.7°C on 11 February.

Perth recorded 25 nights when the minimum temperature was 5°C or less, the least number of such nights since the 24 nights in 2007. The average is 27.

Annual rainfall - very much below average: Perth's annual rainfall for 2009 was 608.2 mm on 108 days, Perth's 10th driest year on record. It was Perth's driest year since the 466.8 mm on 97 days in 2006, which was Perth's driest year on record. The long-term average is 854 mm on about 112 days, whilst last year Perth recorded 807.8 mm on 117 days.

Perth's top 10 driest years
Year
Rainfall
Rain days
Rank
2006
466.8
97
1
1940
508.7
96
2
1914
514.4
111
3
1877
520.2
103
4
1979
559.6
112
5
1969
573.9
87
6
1911
594.7
108
7
1894
602.3
103
8
1977
607.0
94
9
2009
608.2
108
10

Perth's wettest month in 2009 was June with 156.2 mm on 19 days, 20.8 mm below the average of 177 mm. Every month in 2009 saw below average rainfall except November, which recorded 38.2 mm; the average being 22 mm. The wettest day in 2009 was on 19 July with 30.6 mm.

Annual mean sunshine hours - average: Perth's annual mean sunshine hours in 2009 was 8.8 hours, compared with the average of 8.8 hours.

Annual mean temperature and sunshine
Element

2009

Long- term Average

Highest

Year

Lowest

Year Records Commence
Maximum
Temperature (°C)
25.0
24.4
25.2
1978
21.8
1917
1897
Minimum
Temperature (°C)
12.7
12.7
14.9
1988
12.0
1908/2001
1897
Sunshine
(hours per day)
8.8
8.8
9.1
1994
6.8
1923/1965
1898
Annual rainfall and rain days
Element 2009 Long-term Average Highest Year Lowest Year Records Commence
Rainfall (mm)
608.2
854
1338.8
1945
466.8
2006
1876
Rain days
108
111.6
167
1926
87
1969
1876

Daily extremes in 2009
Element 2009 Date Extreme Date

Records Commence

Highest daily maximum (°C)
41.8
16/01/2009
46.2
23/02/1991
1897
Lowest daily maximum (°C)
12.8
23/06/2009
8.8
26/06/1956
1897
Highest daily minimum (°C)
23.7
11/02/2009
29.3
* Several
1897
Lowest daily minimum (°C)
1.5
14/07/2009
−0.7
17/06/2006
1897
Wettest 24 hours to am (mm)
30.6
19/07/2009
120.6
09/02/1992
1876

Denotes * 6 February 1898, 8 February 1933 and 3 February 1962.

Past years in Perth 2000 - 2009
Season
Mean Maximum(°C)
Mean Minimum(°C)
Total Rainfall (mm)
Rain Days
Mean Sunshine (hours per day)
2000
24.5
12.9
796.2
112
8.9
2001
24.2
12.0
688.6
106
8.8
2002
24.5
12.7
737.8
117
8.9
2003
24.5
12.8
853.6
121
8.8
2004
24.5
12.6
637.0
108
8.9
2005
23.5
12.3
874.8
125
8.4
2006
24.8
12.3
466.8
97
9.0
2007
24.4
12.5
703.0
117
8.8
2008
24.6
12.3
807.8
117
8.8
2009
25.0
12.7
608.2
108
8.8

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), or Yanhui Blockley tel: (08) 9263 2222 on weekdays.