Weather in Medan in December

A hard month. December asks something of you. Go in knowing what. You should expect rain on 27 days of the month, which is more days wet than dry.

Medan barely has seasons. December scores 49 out of 100 against a best of 54 in February — a gap small enough that the month you choose matters far less here than the week you choose.

Rain on 27 of the month's 31 days, 8 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 89% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 4 days top 30 °C — hot spells arrive, but they break; the day barely swings — 4.9 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 32.5 °C and the coldest night fell to 21.3 °C, and the wettest single day dropped 107 mm — roughly 43% of the month's rain in one day.

December is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest December on record still delivered 459 mm against 111 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 250 mm average is a reasonable planning figure, not a promise.

Wind is light at 4.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity at 89% is the real story though — it is the number that decides how the day feels, not the 28.8 °C.

How December sits in the year

Temperatures hold steady either side: 29 °C in November, 28.8 here, 29 in January. Nothing about the timing within the month matters much. Rain is the thing that moves: January brings 5 days less of it, so pushing the dates later buys drier weather.

Daylight in December

Medan sits close enough to the equator that daylight barely moves all year — 11.9 hours in December, against a range of just 0.4 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 29 °C in December — warm enough that the water offers no relief from the heat. The sea peaks at 30.4 °C in May and bottoms out at 28.8 °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 Medan versus nearby

If Medan is one option among several, the nearby comparison is worth making. Ipoh is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Kota Kuala Muda is close enough to be a coin toss — within a degree on temperature, 2 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 Medan

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