Weather in Perth in January

Prime time. January is about as good as Perth gets. Highs average 26.4 °C, lows 19.4 °C, and rain falls on 2 days — nothing in the month is working against you.

January is the highest-scoring month of the twelve. The nearest rival is February, and the month at the other end of the year is July.

Rain falls on only 2 days, so an itinerary with no wet-weather fallback is a reasonable risk. 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: 6 days top 30 °C — hot spells arrive, but they break. Across the twenty years measured, the hottest January day reached 37.6 °C and the coldest night fell to 13.2 °C, and the wettest single day dropped 69 mm — roughly 383% of the month's rain in one day.

This is the volatile part. January rainfall has ranged from 0 mm to 81 mm across the twenty years measured — a 81 mm spread around an average of 18 mm. The average is real but almost no individual January looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind sits around 20.2 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity is unremarkable at 65%.

How January sits in the year

Temperatures hold steady either side: 24.6 °C in December, 26.4 here, 26.9 in February. Nothing about the timing within the month matters much.

Daylight in January

January is at or near the longest days of Perth's year: 14 hours of daylight, losing 0.5 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 21.8 °C in January — comfortable for a proper swim. The sea peaks at 22.9 °C in March and bottoms out at 19 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

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

January in Perth versus nearby

If Perth is one option among several, the nearby comparison is worth making. Bunbury is the weaker option in January — 4.6 °C warmer, the same number of rain days. Geraldton is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: January is the answer for Perth. If it is booked out or priced out, February is the next best thing at 0 points behind, and July is the month to keep off the shortlist.

Every month in Perth

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