Weather in Sydney in January

Prime time. January is about as good as Sydney gets. Highs average 25.7 °C, lows 20.3 °C, and rain falls on 12 days — nothing in the month is working against you.

Sydney barely has seasons. January scores 78 out of 100 against a best of 86 in September — a gap small enough that the month you choose matters far less here than the week you choose.

Rain on 12 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 5.3 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest January day reached 37.7 °C and the coldest night fell to 15.7 °C, and the wettest single day dropped 79 mm — roughly 95% of the month's rain in one day.

January is moderately variable: 24 mm in the driest year against 235 mm in the wettest, around an average of 83 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind is light at 11.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 75%, high enough to notice on the warm days without dominating them.

How January sits in the year

Temperatures hold steady either side: 24.3 °C in December, 25.7 here, 25 in February. Nothing about the timing within the month matters much.

Daylight in January

January is at or near the longest days of Sydney's year: 14.2 hours of daylight, losing 0.6 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 23.5 °C in January — comfortable for a proper swim. This is the warmest the water gets all year.

How busy it gets

Shoulder. The value months — prices ease off and you get the place closer to itself.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

January in Sydney versus nearby

If Sydney is one option among several, the nearby comparison is worth making. Central Coast is the weaker option in January — 3.5 °C warmer, 1 day more rain. Katoomba is close enough to be a coin toss — 2.1 °C warmer, the same number of rain days.

So: January works, with September the better month by 8 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Sydney

See all twelve months in Sydney, or where else to go in January.