Sydney’s seasons are inverted from the northern hemisphere, which catches people out when booking.
Summer, December to February
Hot and humid — 19 to 27°C typically, with days above 35 and occasional extremes past 40 when westerlies bring desert air.
This is beach season, school holidays and peak prices. New Year’s Eve and the two weeks either side are the most expensive of the year.
It is also when the southerly buster arrives — a violent cool change that sweeps up the coast on a hot afternoon, dropping the temperature ten degrees in minutes.
The UV is at its most extreme. See the beach article.
Autumn, March to May
The best time to come. Warm days, the sea still warm from summer, low humidity, and the crowds gone. March and April in particular are close to ideal.
Sculpture by the Sea runs along the Bondi to Tamarama cliff path in October–November, not autumn — but Sydney Royal Easter Show is in April.
Winter, June to August
8 to 18°C, dry, and frequently brilliantly clear — Sydney winter days are often blue and still.
Too cold for most visitors to swim, though locals do. The walks, the harbour and the galleries are at their best, and it is the cheapest season.
Vivid runs from late May into June and fills the evenings, pushing accommodation prices back up for three weeks.
Whale season runs from late May to November, with humpbacks visible from the headlands.
Spring, September to November
Warming, with the jacarandas out in late October and November — Kirribilli and the Inner West are covered in purple, and there is a well-known tree in a laneway in Kirribilli with a permanent queue of photographers.
Water warms enough to swim from about November.
Dates worth knowing
26 January — Australia Day, and also marked as Invasion Day and Survival Day with large protest marches. Public holiday.
January — Sydney Festival, three weeks of theatre, music and free outdoor events.
February–March — Mardi Gras, with the parade on Oxford Street.
Late May–June — Vivid.
First Tuesday in November — the Melbourne Cup, when the country stops for three minutes and a great many people take a long lunch.
31 December — the harbour fireworks, watched by around a million people. Vantage points fill from dawn.
Rain
Falls year-round with an autumn peak, in short heavy bursts. Sydney gets more annual rainfall than London — it simply arrives on fewer days.