Cool spring in Perth

Rainfall: Spring rainfall this year in Perth was near average. From September to November, Perth received 157.2 mm over 40 days compared with the average of 156 mm over 30 days. Last spring, Perth recorded 105.8 mm over 33 days. Rainfall totals for individual spring months were: September 91.0 mm (average 81 mm), October 52.8 mm (average 53 mm) and November 13.4 mm (average 22 mm). The wettest day was 6 September when 20.0 mm of rain fell.

Mean daily maximum temperature: The mean daily maximum temperature for Perth this spring of 21.6 degrees Celsius was well below the average of 23.0 degrees. This was the lowest spring mean daily maximum temperature in the 12 years of spring records at the official Perth metropolitan observation site at Mt Lawley. Daily maxima ranged from a cool 15.5 degrees on 9 September to a hot 34.7 degrees on 15 November. Last spring the mean daily maximum temperature was 22.8 degrees.

Mean daily minimum temperature: The mean daily minimum temperature for Perth this spring of 10.4 degrees Celsius was also well below the average of 11.6 degrees. This was the lowest spring mean daily minimum temperature yet recorded at the official Perth metropolitan observation site at Mt Lawley. Daily minima ranged from a cold 1.5 degrees on 1 and 10 September to a mild 17.7 degrees on 28 November. Last spring the mean minimum temperature was 11.3 degrees.

Mean daily sunshine hours: Perth's mean daily sunshine hours this spring was 9.2 hours, which was close to the average of 9.3 hours.

Spring mean temperature and sunshine
Element	Spring 2005	Long term Average	Highest	Year	Lowest	Year	Records Commence
Maximum Temperature (°C)	21.6	23.0	24.1	1969	21.0	1971	1897
Minimum Temperature (°C)	10.4	11.6	13.8	1982	10.4	1952	1897
Sunshine (hours per day)	9.2	9.3	9.8	1978/2002	6.6	1965	1898
Spring rainfall and rain days
Element	Spring 2005	Long term Average	Highest	Year	Lowest	Year	Records Commence
Rainfall (mm)	157.2	156	364.0	1890	34.5	1877	1876
Rain days	40	30	48	1898/1926	12	1969	1876

Spring daily extremes
Element	Spring 2005	Date	Extreme	Date	Records Commence
Highest daily maximum (°C)	34.7	15/11/2005	40.3	* Twice	1897
Lowest daily maximum (°C)	15.5	09/09/2005	9.9	05/09/1951	1897
Highest daily minimum (°C)	17.7	28/11/2005	25.1	24/11/1920	1897
Lowest daily minimum (°C)	1.5	1, 10/09/2005	1.7	11/09/2004	1897
Wettest 24 hours to 9am (mm)	20.0	06/09/2005	68.2	18/10/1995	1876

* Denotes the highest daily maximum temperature recorded on 24 November 1913 and 11 November 2003.

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 John Cramb tel: (08) 9263 2222 on weekdays.