Weather in Mombasa in December

A hard month. December asks something of you. Go in knowing what. Daytime highs average 34.1 °C and the afternoon is not negotiable — outdoor plans move to early morning or evening.

December ranks 9 of 12 in Mombasa: past the worst of the year but short of July, which is the month to book if the dates are open.

This is persistent light rain rather than storms: 15 wet days but only 1 heavy ones. It rarely cancels anything outright, and it rarely fully clears either. A jacket beats an umbrella. Pack for heat management rather than style: shade, water, and a schedule that gives up on the middle of the day.

What the averages hide

Averages flatten a month, and this one hides a few things: 12 days clear 35 °C, so a serious heatwave is normal rather than notable. Across the twenty years measured, the hottest December day reached 38.5 °C and the coldest night fell to 22.4 °C, and the wettest single day dropped 26 mm — roughly 38% of the month's rain in one day.

December is moderately variable: 11 mm in the driest year against 159 mm in the wettest, around an average of 69 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 9.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 74%.

How December sits in the year

Temperatures hold steady either side: 33.1 °C in November, 34.1 here, 35.8 in January. Nothing about the timing within the month matters much. Rain is the thing that moves: January brings 9 days less of it, so pushing the dates later buys drier weather.

Daylight in December

Mombasa sits close enough to the equator that daylight barely moves all year — 12.4 hours in December, against a range of just 0.5 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 28.7 °C in December — warm enough that the water offers no relief from the heat. The sea peaks at 29.4 °C in April and bottoms out at 25.7 °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

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.

December in Mombasa versus nearby

If Mombasa is one option among several, the nearby comparison is worth making. Zanzibar is a better bet in December — 4.4 °C cooler, 4 days more rain. Dar es Salaam is close enough to be a coin toss — 3.9 °C cooler, 7 days more rain.

So: December is a compromise. July is 32 points better and is what Mombasa 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 Mombasa

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