Weather in Cancún in December

Prime time. If you get to pick your dates, December is the one. Highs average 26.8 °C, lows 22.9 °C, and rain falls on 11 days — nothing in the month is working against you.

December ranks 4 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 11 days, 2 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 December reaches 30 °C; the day barely swings — 3.9 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 30.4 °C and the coldest night fell to 17.7 °C, and the wettest single day dropped 39 mm — roughly 57% of the month's rain in one day.

December is moderately variable: 10 mm in the driest year against 147 mm in the wettest, around an average of 68 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 8.9 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 79%, high enough to notice on the warm days without dominating them.

How December sits in the year

Temperatures hold steady either side: 27.4 °C in November, 26.8 here, 26.4 in January. Nothing about the timing within the month matters much.

Daylight in December

December sits at the dark end of Cancún's year — 10.9 hours of daylight against 13.4 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 °C in December — warm enough to stay in as long as you like. 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

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, November is the trade worth considering — 13 points weaker on weather, and materially quieter.

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

December in Cancún versus nearby

If Cancún is one option among several, the nearby comparison is worth making. Mérida is close enough to be a coin toss — 2.7 °C warmer, 5 days less rain. Key West is close enough to be a coin toss — 2.7 °C cooler, 4 days less rain.

So: December is effectively as good as it gets here — 5 points behind February, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Cancún

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