Weather in Adelaide in May

Prime time. May is about as good as Adelaide gets. Highs average 18.8 °C, lows 10.3 °C, and rain falls on 10 days — nothing in the month is working against you.

May ranks 9 of 12 in Adelaide: past the worst of the year but short of March, which is the month to book if the dates are open.

Rain on 10 days, 1 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: it never really gets hot: not one day in an average May reaches 30 °C. Across the twenty years measured, the hottest May day reached 29.1 °C and the coldest night fell to 4.2 °C, and the wettest single day dropped 30 mm — roughly 57% of the month's rain in one day.

May is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest May on record still delivered 79 mm against 8 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 53 mm average is a reasonable planning figure, not a promise.

Wind is light at 8.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 73%.

How May sits in the year

The month is on the way down: 4.6 °C cooler than April, with June dropping another 3.3 °C. The first week and the last are not the same trip.

Daylight in May

May sits at the dark end of Adelaide's year — 10.3 hours of daylight against 14.5 at midsummer, losing 0.7 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

Despite being inland, the year stays fairly even: 23.5 °C between the year's warmest afternoons and coldest nights.

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 Adelaide versus nearby

If Adelaide is one option among several, the nearby comparison is worth making. Gawler is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Whyalla is a better bet in May — within a degree on temperature, 4 days less rain.

So: May works, with March the better month by 14 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Adelaide

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