Friday 1 September, 2006

SEASONAL CLIMATE SUMMARY - WESTERN AUSTRALIAN REGIONAL OFFICE

Perth's driest and equal warmest winter on record

Rainfall - record low: The city received a record low winter rainfall of 230.4 mm over 35 days in 2006, compared with the average of 485 mm over 50 days. The previous driest winter was 260.0 mm on 40 days in 1940. Last winter, Perth recorded 438.4 mm over 45 days. Rainfall totals for individual months this winter were: June 24.6 mm (average 179 mm), July 81.0 mm (average 171 mm) and August 124.8 mm (average 135 mm). The wettest day in winter was 15 August when 27.0 mm of rain fell.

Perth's top 10 driest winter's
Season	Rainfall (mm)	Rain Days	Ranking
2006	230.4	35	1
1940	260.0	40	2
1881	303.2	39	3
1971	306.7	47	4
1877	307.6	48	5
1979	314.0	45	6
1914	316.7	43	7
1977	333.2	46	8
1894	333.7	50	9
1976	341.8	40	10

Mean daily maximum temperature: The mean daily maximum temperature for Perth this winter of 19.7°C was the equal highest mean daily maximum temperature on record, also recorded in 1976 and 1983. The average for winter is 18.6°C. Last winter the mean daily maximum temperature was 18.3°C. Daily values ranged from a cold 14.6 degrees on 21 July to a warm 26.7°C on the 29 August.

Mean daily minimum temperature: The mean daily minimum temperature for Perth this winter of 7.4°C was below the average of 8.3°C. This was the second lowest winter mean daily minimum temperature recorded at the official Perth metropolitan observation site at Mt Lawley. Last winter the mean daily minimum temperature was 7.9°C. Daily minima ranged from a cold -0.7°C on 17 June, the lowest temperature ever recorded at the Mt Lawley site, to a warm 17.0°C on 7 August.

Mean daily sunshine hours: Perth's mean daily sunshine hours this winter was 7.1, which was above the long term average of 6.3 hours and the second sunniest winter on record.

* Denotes the lowest all-time minimum temperature on record on the following dates: 15 July 1997 and 27 July 1998

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) and Glenn Cook Western Australia Climate Services Centre
on, tel: (08) 9263 2222, office hours.