Monday 2 February 2009 - Monthly Climate Summary for Perth - Product Code: IDCKGC11LO

Another hot January for Perth

Mean daily maximum temperature - well above average: Perth's mean daily maximum temperature for January was 32.5°C, compared with the average of 30.5°C. January 2009 ranked as the equal sixth hottest on record with 1981, 1961 and 1956 since observations commenced in 1897. Daily maxima ranged from a mild 25.9°C on the 13th to a very hot 41.8°C on the 16th. Last year the mean daily maximum temperature for January was 32.8°C, Perth's equal fourth hottest January on record.

Perth's top 10 mean maximum temperatures
for January
Year
Mean Maximum Temperatures (°C)
Departure from normal
Ranking
1962
34.4
+3.9
1
1978
33.3
+2.8
2
1974
33.2
+2.7
3
2008
32.8
+2.3
4
1992
32.8
+2.3
4
2009
32.5
+2.0
6
1981
32.5
+2.0
6
1961
32.5
+2.0
6
1956
32.5
+2.0
6
1997
32.2
+1.7
10
1980
32.2
+1.7
10

Number of days of 35°C or higher: During January 2009, Perth recorded 12 days when the temperature was 35°C or higher. This was the greatest such number of days for January since 1992, then 13 days. The most number of days of 35°C or higher for January  was 17 days in 1962, the hottest January on record for Perth with a mean daily maximum temperature of 34.4°C.

Mean daily minimum temperature - above average: Perth's mean daily minimum temperature in January was 18.7°C, compared with the average of 17.7°C.  Daily minima ranged from a cool 12.0°C on the 13th to a warm 22.7°C on the 16th.

Rainfall - well below average: The city received 0.2 mm on 1 day during January compared with the average of 10 mm on about 2 days. Historically, January rainfall has ranged from zero on 13 occasions to 139.0 mm in 2000.  Last January Perth registered zero rainfall.
 

January monthly mean temperature and sunshine
Element

2009

Long- term Average

Highest

Year

Lowest

Year Records Commence
Maximum
Temperature (°C)
32.5
30.5
34.4
1962
26.3
1939
1897
Minimum Temperature (°C)
18.7
17.7
20.9
1978
15.6
3 years
1897
Sunshine
(hours per day)
11.4
11.6
12.6
1974
8.3
1920
1898
January rainfall and rain days
Element 2009 Long-term Average Highest Year Lowest Year Records Commence
Rainfall (mm)
0.2
10
139.0
2000
0.0
13 years
1876
Rain days
1
2.3
8
1916/1990
0
13 years
1876

January daily extremes
Element 2009 Date Extreme Date

Records Commence

Highest daily maximum (°C)
41.8
16/01/2009
45.8
31/01/1991
1897
Lowest daily maximum (°C)
25.9
13/01/2009
19.7
** Twice
1897
Highest daily minimum (°C)
22.7
16/01/2009
27.8
21/01/1989
1897
Lowest daily minimum (°C)
12.0
13/01/2009
8.9
25/01/2001
1897
Wettest 24 hours to 9am (mm)
0.2
13/01/2009
104.0
22/01/2000
1876

* Denotes lowest January maximum temperature on record has occurred on the following dates: 19 January 1939 and 3 January 2007.

Climate of Perth in February
Like January, February in Perth is typically sunny and warm to hot, though day-time temperatures are, on average, slightly higher than those in January. A mean of 13 mm of rainfall occurs on about two days during the month.

February monthly mean temperatures and sunshine
Element Average Highest Year Lowest Year

Records
Commence

Maximum temperature (°C)
31.2
35.1
1985
26.5
1926
1897
Minimum temperature (°C)
18.0
22.7
1985
15.6
1931
1897

Sunshine
(hours per day)

11.0
12.0
3 years
7.7
1955
1898
February monthly rainfall and rain days
Element
Average
Highest
Year
Lowest
Year
Records Commence
Rainfall (mm)
13
166.3
1955
0.0
17 years
1876
Rain days
2.2
8
3 years
0
17 years
1876

February daily extremes
Element
Highest
Date
Lowest
Date
Records Commence
Maximum temperature (°C)
46.2
23/02/1991
19.0
17/02/1914
1897
Minimum temperature (°C)
29.3
** 3 years
8.7
01/02/1902
1897
Rainfall 24 hours to 9am (mm)
120.6
09/02/1992
n/a
n/a
1876

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

Very hot days in February: On average, Perth can expect one day when the maximum temperature is 40°C or higher. The highest number of 40°C or higher days in February was four in 1933 and 1985. The last time Perth recorded a 40°C or higher February day was on 28 February 2008 when 41.5°C was recorded.

Hot days in February: On average, Perth can expect approximately 12 days when the maximum temperature is 32°C or higher. The highest number of hot days in February was 23 in 1996.

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