Wednesday, 1 April 2009 - Monthly Climate Summary for Perth - Product Code: IDCKGC11LO

Dry start to 2009 for Perth 

Year to date rainfall - below average: The total rainfall for January to March this year was 15.2 mm recorded on 10 days, making it the driest start to a year in Perth since the 2.0 mm in 2004. The average is 42 mm on 9 days. Last year Perth recorded 61.8 mm on 5 days for the first three months of the year.

March Rainfall - below average: The city received 6.8 mm of rainfall on 6 days in March, compared with the average of 19 mm on about 5 days. Historically, March rainfall in Perth has ranged from 0.0 mm on 6 occasions, to 145.2 mm in 1934. The wettest day in March 2009 was the 21st when 2.8 mm was recorded. Last March, Perth registered 14.2 mm of rainfall on 3 days.

Mean daily maximum temperature - near average: Perth's mean daily maximum temperature in March was 29.0°C, which was the lowest mean daily maximum temperature for Perth in March since 2000, then 28.8°C. The average for March is 29.4°C. Daily maxima ranged from a mild 23.5°C on the 2nd and 22nd, to a very hot 39.8°C on the 15th, which was Perth's highest daily maximum temperature in March since the 42.4°C on 7 March 2007 (Perth's hottest ever March day on record). 

Mean daily minimum temperature - below average: Perth's mean daily minimum temperature in March was 15.1°C, which was the lowest mean daily minimum temperature recorded for March at the official Perth (Mt Lawley) site since records commenced in 1994. The average for March is 16.5°C.  Daily minima ranged from a cool 7.7°C on the 3rd to a warm 21.7°C on the 1st.

March monthly mean temperature and sunshine
Element

2009

Long- term Average

Highest

Year

Lowest

Year Records Commence
Maximum
Temperature (°C)
29.0
29.4
31.8
1978
24.4
1927
1897
Minimum Temperature (°C)
15.1
16.5
20.0
1988
13.5
1900
1897
Sunshine
(hours per day)
9.6
9.5
10.6
2001/07
5.5
1927
1898
March rainfall and rain days
Element 2009 Long-term Average Highest Year Lowest Year Records Commence
Rainfall (mm)
6.8
19
145.2
1934
0.0
6 years
1876
Rain days
6
4.5
10
1915
0
6 years
1876

March daily extremes
Element 2009 Date Extreme Date

Records Commence

Highest daily maximum (°C)
39.8
15/03/2009
42.4
07/03/2007
1897
Lowest daily maximum (°C)
23.5
* Twice
16.4
27/03/1968
1897
Highest daily minimum (°C)
21.7
01/03/2009
28.3
02/03/1934
1897
Lowest daily minimum (°C)
7.7
03/03/2009
6.3
27/03/2007
1897
Wettest 24 hours to 9am (mm)
2.8
21/03/2009
77.0
09/03/1934
1876

* Denotes lowest daily minimum temperature recorded on both the 2nd and 22nd of March 2009.

Climate of Perth in April
Sunny and pleasantly mild autumn days are common in April in the transition between summer and winter. Wet weather does occur, especially later in the month, and mean rainfall and rain days are about double those of March.

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

Records
Commence

Maximum temperature (°C)
25.5
28.2
1978/1999
21.0
1968
1897
Minimum temperature (°C)
13.6
17.3
1978
11.6
1914
1897

Sunshine (hours per day)

8.2
9.3
1920
4.4
1926
1898
April monthly rainfall and rain days
Element
Average
Highest
Year
Lowest
Year
Records Commence
Rainfall (mm)
44
153.6
2008
0.0
3 years
1876
Rain days
6.9
19
1926
0
3 years
1876

April daily extremes
Element
Highest
Date
Lowest
Date
Records Commence
Maximum temperature (°C)
37.6
09/04/1910
13.6
16/04/1919
1897
Minimum temperature (°C)
24.4
02/04/1913
4.1
20/04/1914
1897
Rainfall 24 hours to 9am (mm)
69.6
17/04/2002
n/a
n/a
1876

Hot days in April: On average, Perth can expect about two hot days, when the maximum temperature is 32°C or higher. The greatest number of such hot days in April was eight in 1991. Last year, Perth recorded one such day.

Latest 35-degree day of the season: The latest maximum temperature of 35.0°C or higher in the season occurred on 22 April 1989, with 35.2°C.

Cold days in April: Since 1897, Perth has recorded six cold days in April, when the maximum temperature was 15°C or lower. They occurred one day each in 1900, 1919, 1931, 1963 and two days in 1970. The earliest cold day in the year occurred on 15 April 1900, when a maximum temperature of 14.5°C was recorded.

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.