Near average rainfall for August in Perth

Rainfall near average: The city received 124.6 millimetres of rainfall over 12 days in August compared with the average of 135 mm over 16 days. Last August Perth recorded 175.6 mm over 21 days. Total rainfall for January to August this year was 712.6 mm compared with the average of 690 mm, making it the wettest January to August period since the 717.4 mm in 2000. The wettest January to August period on record was 1124.1 mm in 1945.

Mean daily maximum temperature near average: Perth's mean daily maximum temperature in August was 18.4 degrees Celsius compared with the average of 18.5 degrees. Daily maxima ranged from a cold 14.6 degrees on the 18th and 30th to a warm 24.8 degrees on the 1st, the warmest August day for three years.

Mean daily minimum temperature near average: Perth's mean daily minimum temperature in August was 8.0 degrees Celsius, compared with the average of 8.1 degrees. Minima ranged from a very cold 1.4 degrees on the 19th, the equal second coldest August night on record, to a mild 13.2 degrees on the 28th.

Mean daily sunshine hours near average: Perth's mean daily sunshine hours in August was 6.9, compared to the average of 7.2 hours. (This is a preliminary figure based on the available data at the time of the media release. Please check updated mean sunshine hours from Daily Weather Observations for Perth in early September).

August monthly mean temperature and sunshine
Element	2005	Long- term Average	Highest	Year	Lowest	Year	Records Commence
Maximum Temperature (°C)	18.4	18.5	20.3	1902	16.3	1932	1897
Minimum Temperature (°C)	8.0	8.1	11.5	1977/1983	6.9	1956/2001	1897
Sunshine (hours per day)	6.9	7.2	8.4	1902	4.2	1945	1898
August monthly rainfall and rain days
Element	2005	Long-term Average	Highest	Year	Lowest	Year	Records Commence
Rainfall (mm)	124.6	135	318.3	1945	11.8	1902	1876
Rain days	12	16	29	1955	4	1902/1978	1876

August daily extremes
Element	2005	Date	Extreme	Date	Records Commence
Highest daily maximum (°C)	24.8	01/08/2005	27.8	21/08/1940	1897
Lowest daily maximum (°C)	14.6	18 & 30/08/2005	9.9	05/08/1951	1897
Highest daily minimum (°C)	13.2	28/08//2005	16.6	13/08/1976	1897
Lowest daily minimum (°C)	1.4	19/08//2005	1.3	21/08/2000	1897
Wettest 24 hours to 9am (mm)	34.2	17/08/2005	73.9	14/08/1945	1876

Climate of Perth in September

September is the first month of spring and in Perth a warm drying trend is often experienced. Monthly rainfall and the number of wet days generally decreases, whilst maximum and minimum temperatures and the number of sunshine hours increases, heralding the end of the winter season.

September monthly mean temperatures and sunshine
Element	Average	Highest	Year	Lowest	Year	Records Commence
Maximum temperature(°C)	20.1	22.6	1987	16.8	1915	1897
Minimum temperature(°C)	9.5	12.4	1988	8.0	2004	1897
Sunshine (hours per day)	7.7	8.8	4 years	4.9	1907	1898
September monthly rainfall and rain days
Element	Average	Highest	Year	Lowest	Year	Records Commence
Rainfall (mm)	81	199.1	1923	8.7	1916	1876
Rain days	15	26	1915	4	1877	1876

September daily extremes
September daily extremes Element	Highest	Date	Lowest	Date	Records Commence
Maximum temperature (°C)	32.7	30/09/1918	11.4	17/09/1917	1897
Minimum temperature (°C)	19.5	08/09/1916	1.7	11/09/2004	1897
Rainfall 24 hours to 9am (mm)	51.8	14/09/1984	n/a	n/a	1876

Warm days in September: On average, Perth can expect two days when the maximum temperature is 25 degrees or higher. The record is 10 days in Perth's warmest September on record, 1987, when the mean maximum temperature was 22.6 degrees.

Cold days in September: On average, Perth can expect a maximum temperature of 15 degrees or lower on about one day in every 5 years. The record is four days in 1903 and there was one such day in 2004.

Cold nights in September: On average, Perth can expect three nights in September when the minimum is 5 degrees or lower. The record is seven nights in 2004.

Earliest 32-degree day of the season (hot day): The earliest 32-degree maximum temperature of the season was on 18 September 1988, when 32.3 degrees was recorded, the second highest maximum temperature for September on record.

September top 10 hottest			September top 10 coldest
Position	Date	Max temp °C	Position	Date	Max temp°C
1	30 September 1918	32.7	1	17 September 1917	11.4
2	18 September 1988	32.3	2	04 September 1931	11.6
3	22 September 1961	32.2	3	01 September 1931	12.1
4	26 September 1961	31.3	4	16 September 1937	12.5
5	14 September 1987	30.9	5	14 September 1947	12.7
6	28 September 1990	30.7	6	17 September 1915	12.9
6	20 September 1994	30.7	6	19 September 1923	12.9
8	12 September 1939	30.6	6	12 September 1950	12.9
8	21 September 1954	30.6	9	20 September 1904	13.0
8	27 September 1954	30.6	10	12 September 1916	13.1
-	-	-	10	10 September 1925	13.1

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