Weather in Trincomalee in December

Shoulder season. December is shoulder season in Trincomalee — cheaper, quieter, and a genuine gamble. You should expect rain on 20 days of the month, which is more days wet than dry.

December ranks 6 of 12 in Trincomalee: past the worst of the year but short of February, which is the month to book if the dates are open.

Rain on 20 of the month's 31 days, 10 of them heavy. At that frequency a wet-weather backup is not a contingency, it is the itinerary — book the indoor things first and treat the clear days as the bonus. Natural fibres and a second shirt for the day. At 82% nothing dries, including you.

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 — 2.6 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 30.2 °C and the coldest night fell to 22.1 °C, and the wettest single day dropped 90 mm — roughly 30% of the month's rain in one day.

December is moderately variable: 58 mm in the driest year against 672 mm in the wettest, around an average of 304 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 15.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 82%, high enough to notice on the warm days without dominating them.

How December sits in the year

Temperatures hold steady either side: 28.5 °C in November, 27.8 here, 27.5 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

Trincomalee sits close enough to the equator that daylight barely moves all year — 11.6 hours in December, against a range of just 1 hour across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 27.7 °C in December — warm enough that the water offers no relief from the heat. The sea peaks at 30.3 °C in May and bottoms out at 27.2 °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.

December in Trincomalee versus nearby

If Trincomalee is one option among several, the nearby comparison is worth making. Kandy is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Jaffna is close enough to be a coin toss — within a degree on temperature, 3 days less rain.

So: December works, with February the better month by 17 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Trincomalee

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