Perth, capital of Western Australia, sits on the Swan River near the Indian Ocean coast at approximately 31.95°S, 115.86°E. It has a Mediterranean climate (Köppen Csa) with hot, dry summers and mild, wet winters, and is the sunniest capital city in Australia, enjoying around 3,200 hours of sunshine a year and clear skies roughly 70% of the time. Being in the Southern Hemisphere, its seasons are the reverse of the Northern.

Summer, from December to February, is hot, sunny and very dry, with February the hottest month — average highs around 31–32°C and warm nights. Heatwaves can push temperatures past 40°C, but the standout feature is the 'Fremantle Doctor', a strong, reliable afternoon sea breeze off the Indian Ocean that sweeps in and takes the edge off the heat, which is why many locals hit the beach in the morning before the wind rises. Rain in summer is rare and usually limited to brief thunderstorms.

Winter, from June to August, is mild and comparatively wet. July, the coldest month, averages daytime highs around 18°C and nights near 8°C, occasionally dropping to a couple of degrees inland. Coastal frost is essentially unknown. This is the green, rainy season, when cold fronts sweeping off the Southern Ocean deliver most of the year's rain, often in short, sharp downpours with the odd thunderstorm.

Perth is dry by the standards of Australia's other capitals, with rainfall of roughly 700–880 mm a year, and it is strongly seasonal: well over three-quarters falls in the cooler months between May and September, while summers are almost rainless. June and July are the wettest months. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

The 'Fremantle Doctor' — the cooling afternoon sea breeze — is the defining character of Perth's warm-season weather and one of the most consistent sea breezes in the world. Perth never gets tropical cyclones directly, as the local seas are too cool, but the decaying remnants of northern cyclones can occasionally sweep down in late summer and autumn to deliver unusually heavy, record-setting rain.

To follow any single measurement in Perth more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.