Weather in Kota Bharu in September

Shoulder season. September is shoulder season in Kota Bharu — cheaper, quieter, and a genuine gamble. You should expect rain on 28 days of the month, which is more days wet than dry.

September ranks 8 of 12 in Kota Bharu: past the worst of the year but short of February, which is the month to book if the dates are open.

Rain on 28 of the month's 30 days, 5 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. Pack for 30.3 °C days and 26.2 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 19 days top 30 °C — hot spells arrive, but they break; the day barely swings — 4.1 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest September day reached 33.1 °C and the coldest night fell to 24.5 °C, and the wettest single day dropped 29 mm — roughly 16% of the month's rain in one day.

September is one of the reliable ones — rainfall has stayed between 108 mm and 248 mm across all twenty years, a narrow enough band that the 179 mm average is something you can plan against rather than merely quote.

Wind is light at 5.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 80%, high enough to notice on the warm days without dominating them.

How September sits in the year

Temperatures hold steady either side: 30.5 °C in August, 30.3 here, 29.6 in October. Nothing about the timing within the month matters much.

Daylight in September

Kota Bharu sits close enough to the equator that daylight barely moves all year — 12.2 hours in September, 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 29.5 °C in September — warm enough that the water offers no relief from the heat. The sea peaks at 30.5 °C in May and bottoms out at 27.7 °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

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

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

September in Kota Bharu versus nearby

If Kota Bharu 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, 4 days less rain. Kota Kuala Muda is close enough to be a coin toss — within a degree on temperature, 1 day less rain.

So: September is a compromise. February is 26 points better and is what Kota Bharu 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 Kota Bharu

See all twelve months in Kota Bharu, or where else to go in September.