Weather in Singapore in September

How September compares

September is the 7th warmest month of the year in Singapore and ranks 44th of 134 destinations we compare for September - see where else is hot in September. Against London's average high of 18.6°C in September, Singapore is 9.8°C warmer by day and 14.5°C warmer at night.

Daytime and night-time in September

The typical September day in Singapore peaks at 28.4°C, but that is an average: the warmest 10% of days reach 29.2°C or more. About 100% of days top 25°C and 1 in 26 pass 30°C. Nights average 25.7°C; one night in ten drops to 24.7°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest September day here reached 32.9°C (2019-09-22) and the coldest night 23.6°C (2020-09-14).

Rain in September

Wet (more than 8 rainy days): about 24 days with 1 mm or more, 166 mm in total. Year to year it varies a lot - the wettest September was 2020 with 296 mm, the driest 1994 with 66 mm. Humidity averages 82%, which makes the heat feel heavier than the thermometer suggests.

Sea temperature in September

The sea averages 29.0°C - warm enough to swim (22°c+). Depending on the year it ranges from 28.6°C to 29.5°C. For the warmest sea here, come in May (30.1°C).

Sunshine and daylight

Around 2.6 hours of sunshine a day (estimated from cloud cover), 12.0 hours of daylight: the sun rises about 06:56 and sets about 19:03 local time in mid-September. Average cloud cover is 79%.

Is September a good time to visit Singapore?

It is a reasonable choice: hot days but expect showers. The best months for Singapore on our scoring are July, June, March; months averaging 25°C or more: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec.

Warm evenings, with humidity the main catch

September's heat is persistent rather than extreme: only 4% of days reach 30°C, but humidity averages 82%. That makes light, loose clothing a more useful packing choice than outfits suited to a British September. Plan demanding outdoor time with breaks, and avoid treating midday as the best slot for a long walk. Evenings offer little temperature relief, with the average low around 26°C, so do not expect the fresh nights you might get at home. This suits travellers who enjoy warmth throughout the day and evening; it is less comfortable if you rely on cooler weather to stay active outdoors.

Plan around rain, not guaranteed sunshine

Rain is a regular consideration, with about 24 days recording at least 1 mm, so keep covered alternatives available rather than fixing every day around outdoor plans. That figure does not mean rain lasts all day, but it does make a reliably dry trip a poor expectation. Sunshine averages about 2.6 hours within 12 hours of daylight: there is plenty of daylight for getting around, but much less direct sun. Pack a compact umbrella, a light waterproof layer and footwear you are comfortable wearing in wet conditions. September works better for a flexible visit than for a holiday whose success depends on clear skies.