Weather in Jakarta in January

Shoulder season. January sits in between. You will get good days and you will lose some. You should expect rain on 29 days of the month, which is more days wet than dry.

January ranks 5 of 12 in Jakarta: past the worst of the year but short of August, which is the month to book if the dates are open.

Rain on 29 of the month's 31 days, 12 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 84% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 5 days top 30 °C — hot spells arrive, but they break; the day barely swings — 3.5 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest January day reached 33.8 °C and the coldest night fell to 23.5 °C, and the wettest single day dropped 93 mm — roughly 26% of the month's rain in one day.

January is moderately variable: 93 mm in the driest year against 769 mm in the wettest, around an average of 353 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind is light at 11.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, high enough to notice on the warm days without dominating them.

How January sits in the year

Temperatures hold steady either side: 29.4 °C in December, 28.8 here, 28.5 in February. Nothing about the timing within the month matters much.

Daylight in January

Jakarta sits close enough to the equator that daylight barely moves all year — 12.4 hours in January, against a range of just 0.7 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 28.6 °C in January — warm enough that the water offers no relief from the heat. The sea peaks at 29.9 °C in May and bottoms out at 28.6 °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.

January in Jakarta versus nearby

If Jakarta is one option among several, the nearby comparison is worth making. Bandung is close enough to be a coin toss — 2.5 °C cooler, 1 day less rain. Bandar Lampung is close enough to be a coin toss — within a degree on temperature, 3 days less rain.

So: January works, with August the better month by 18 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Jakarta

See all twelve months in Jakarta, or where else to go in January.