Sydney weather in December
Sydney averages 26°C by day and 18°C at night in December, with the sea at 21°C and about 65 mm of rain in the month. That is about 2°C warmer than November.
Day
26°C
Night
18°C
Sea
21°C
Rain
65 mm
Flight from London
20½h
What December feels like
December is hot in Sydney: proper beach weather.
The sea is 21°C: fine for swimming without a wetsuit.
Rain is occasional: about 65 mm in the month.
That is 17°C warmer than an average December day in London.
Of the 56 sun destinations we track, Sydney is the #25 warmest in December.
Going to Sydney in December?
Share the TikToks and Instagram Reels you've saved for Sydney to Dream Trip. It finds the places, pins them on a map and builds your days around them.
Want it warmer in December?
These are hotter than Sydney this month for at most an hour and a half more flying:
Sydney weather by month
December is highlighted. Compare with November and January, or see the full year in Sydney.
Sydney in December: quick answers
Is Sydney hot in December?
December is hot in Sydney: proper beach weather. Average highs are 26°C and lows 18°C.
Can you swim in Sydney in December?
The sea is 21°C: fine for swimming without a wetsuit.
Does it rain in Sydney in December?
Rain is occasional: about 65 mm in the month.
What is the warmest month in Sydney?
January, at an average high of 27°C. The coolest is June at 17°C.
How long is the flight to Sydney from the UK?
About 20½h direct from London, estimated from the 17,016 km distance. Check your airline for exact times.
Still choosing? See where is hot in December for every destination ranked by temperature, sea and flight time.
How we measured this
Averages of every day in December from 2016 to 2025, from the Open-Meteo historical weather archive (ECMWF ERA5 reanalysis). Sea temperature is the 2023 to 2025 average from the Open-Meteo marine archive. Rain is the average monthly total. Reanalysis describes an area about 25 km across, so sheltered resorts can run a degree or two warmer. Flight time is a distance-based estimate from London Heathrow.
Planning Sydney in December?
Save the restaurants, beaches and views you find on TikTok and Instagram for Sydney straight to a map, then let Dream Trip turn them into a day-by-day plan.
