Weather in Cancún in May

Shoulder season. May is shoulder season in Cancún — cheaper, quieter, and a genuine gamble. Highs average 30.3 °C, lows 25.4 °C, and rain falls on 12 days — nothing in the month is working against you.

May ranks 7 of 12 in Cancún: past the worst of the year but short of February, which is the month to book if the dates are open.

Rain on 12 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 30.3 °C days and 25.4 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 21 days top 30 °C, making the heat continuous rather than occasional; the day barely swings — 4.9 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest May day reached 32.7 °C and the coldest night fell to 20.4 °C, and the wettest single day dropped 64 mm — roughly 70% of the month's rain in one day.

May is moderately variable: 10 mm in the driest year against 228 mm in the wettest, around an average of 92 mm. Roughly two Mays in three land near that average, and the third does something else entirely.

Wind is light at 8.5 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 May sits in the year

Temperatures hold steady either side: 29.5 °C in April, 30.3 here, 29.7 in June. Nothing about the timing within the month matters much. Rain is the thing that moves: June brings 6 days more of it, so the earlier half of a flexible trip is the safer half.

Daylight in May

May is at or near the longest days of Cancún's year: 13.1 hours of daylight, gaining 0.4 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 27 °C in May — warm enough that the water offers no relief from the heat. The sea peaks at 29 °C in August and bottoms out at 25.1 °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

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

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

May in Cancún versus nearby

If Cancún is one option among several, the nearby comparison is worth making. Mérida is the weaker option in May — 5.7 °C warmer, 2 days less rain. Key West is a better bet in May — 3.2 °C cooler, 2 days more rain.

So: May is a compromise. February is 23 points better and is what Cancún 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 Cancún

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