Weather in Cairns in August

Prime time. August is about as good as Cairns gets. Highs average 26.6 °C, lows 18.6 °C, and rain falls on 6 days — nothing in the month is working against you.

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

Rain falls on only 6 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

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest August day reached 35.2 °C and the coldest night fell to 11.5 °C, and the wettest single day dropped 29 mm — roughly 94% of the month's rain in one day.

This is the volatile part. August rainfall has ranged from 0 mm to 124 mm across the twenty years measured — a 124 mm spread around an average of 31 mm. The average is real but almost no individual August looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 6.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, high enough to notice on the warm days without dominating them.

How August sits in the year

Temperatures hold steady either side: 25.3 °C in July, 26.6 here, 29 in September. Nothing about the timing within the month matters much.

Daylight in August

August sits at the dark end of Cairns's year — 11.5 hours of daylight against 13.1 at midsummer, gaining 0.4 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

Sea temperature

The sea sits at about 24.7 °C in August — warm enough to stay in as long as you like. The sea peaks at 29.2 °C in February and bottoms out at 24.7 °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.

August in Cairns versus nearby

If Cairns is one option among several, the nearby comparison is worth making. Port Douglas is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Townsville is close enough to be a coin toss — within a degree on temperature, 4 days less rain.

So: August is the answer for Cairns. If it is booked out or priced out, July is the next best thing at 7 points behind, and December is the month to keep off the shortlist.

Every month in Cairns

See all twelve months in Cairns, or where else to go in August.