Perth - Weather and Climate

Perth receives moderate though highly seasonal rainfall, making it the fourth wettest capital city after Darwin, Sydney and Brisbane. Summers are generally hot and dry, lasting from December to late
March, with February generally being the hottest month of the year, whilst winters are relatively cool and wet, making Perth a classic example of a Mediterranean climate (Köppen climate classification CSa).

Summer is not completely devoid of rain with sporadic rainfall in the form of short-lived thunderstorms, weak cold fronts and on very rare occasions decaying tropical cyclones from Western Australia's north-west which can bring significant falls. The highest ever recorded temperature in Perth was 46.2 °C (115.2 °F) on 23 February 1991, although Perth Airport recorded 46.7 °C (116.1 °F) on the same day. On most summer afternoons a sea breeze, also known as "The Fremantle Doctor", blows from the south-west, providing relief from the hot north-easterly winds. Temperatures often fall below 30 °C (86 °F) a few hours after the arrival of the wind change. Perth is a particularly sunny city for a Mediterranean climate, receiving between 2800 and 3000 hours of annual sunshine.

Winters are relatively cool and wet, with most of Perth's annual rainfall falling between May and September. The lowest temperature recorded in Perth was −0.7 °C (31 °F) on 17 June 2006.[40] The lowest temperature within the Perth metropolitan area was −3.4 °C (26 °F) on the same day at Jandakot Airport.

Though most rainfall occurs during winter, the wettest day ever was on 9 February 1992 when 120.6 millimetres (4.75 in) fell. The rainfall pattern has changed in Perth and Southwest Western Australia since the mid-1970s. A significant reduction in winter rainfall has been observed with a greater number of extreme rainfall events in the summer months, such as slow-moving storms on 8 February 1992 which brought 121 millimetres (4.8 in) of rain, and a severe thunderstorm on 22 March 2010, which brought 40.2 millimetres (1.58 in) and caused significant damage in the metropolitan area.