Summer in Sydney
Sydney Weather in January
On average, Sydney sees a top of 27°C and an overnight low of 20°C in January, with around 12 rain days and 100mm of total rainfall. UV is typically extreme, 11-13.
27°C
20°C
100mm
12
What January is like in Sydney
January is Sydney's hottest month. Temperatures regularly push past 30°C, with occasional scorchers above 40°C when hot westerly winds blow off the inland. Sea breezes from the northeast typically moderate the coast by mid-afternoon. Afternoon thunderstorms can develop quickly over the western suburbs and sweep east, bringing heavy rain, lightning and occasionally hail. Sydney Harbour water temperature peaks around 23-24°C, making it the best month for ocean swimming. Humidity is high and UV extreme — sunburn can occur in as little as 10 minutes around midday.
These figures are long-term averages, not a forecast — for today's actual conditions and the week ahead, check the live Sydney weather forecast. Averages are useful for planning travel, events or what to pack, but any single January can run warmer, cooler, wetter or drier than the long-term normal.