Weather in Cairns in May

A good month. May is a solid month to be in Cairns. The heat itself is manageable at 26.7 °C, but 85% humidity is what you will actually feel.

May ranks 5 of 12 in Cairns: past the worst of the year but short of August, which is the month to book if the dates are open.

Rain on 14 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Natural fibres and a second shirt for the day. At 85% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 5.8 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest May day reached 30.8 °C and the coldest night fell to 13.2 °C, and the wettest single day dropped 71 mm — roughly 69% of the month's rain in one day.

May is moderately variable: 11 mm in the driest year against 236 mm in the wettest, around an average of 103 mm. Roughly two Mays in three land near that average, and the third does something else entirely.

Wind is light at 6.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity at 85% is the real story though — it is the number that decides how the day feels, not the 26.7 °C.

How May sits in the year

Temperatures hold steady either side: 28.1 °C in April, 26.7 here, 25.5 in June. Nothing about the timing within the month matters much.

Daylight in May

May sits at the dark end of Cairns's year — 11.3 hours of daylight against 13.1 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

Sea temperature

The sea sits at about 26.6 °C in May — 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

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.

May 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 a better bet in May — within a degree on temperature, 9 days less rain.

So: May is a compromise. August is 21 points better and is what Cairns is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Cairns

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