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Singapore Weather in September

What to expect from the Singapore weather in September, including average temperatures, rainfall and humidity.

Marina Bay sands with sunshine and clouds.

Weather in Singapore in September

September comes at the end of the Southwest Monsoon period in Singapore and brings with it a slight lull in the rain. 

You can still expect thunderstorms in the afternoons however, and occasional ‘Sumatra squalls’ (thunderstorms originating in Sumatra and traveling eastward across Singapore) can also be expected in the mornings.   

Average monthly temperatures in September are 28°C (82°F). Humidity is average for Singapore with a 80.7% average while rainfall is fairly low for Singapore with rain expected less than half of the days in the month.

Click here to read about the best time to visit Singapore.

Singapore temperature in September

Singapore’s average day time maximum temperature in September is 31.6°C (89°F), with an average minimum temperature of 25.2°C (78°F) and a 24-hour average of 28.0°C (83°F).

How much does it rain in Singapore in September?

It rains on average 13 out of 30 days during September in Singapore, making it one of the least rainy months of they year, although you can still expect it to rain more than one day out of three. 

Short duration thunderstorms in the afternoon are common and occasional morning thunderstorms too. 

Be sure to carry an umbrella with you when you are out and about as the rain can come on suddenly. It’s also a good idea to find somewhere dry to sit and wait it out when it does come. 

With average rainfall of 124.9mm it is a fairly dry month when it comes to rain in Singapore (compared to 105.1mm in January and 331.9mm in December).

Singapore Humidity in September

Relative humidity in September ranges from a minimum average of 62.2% and a maximum average of 93.8% and a 24-hour daily average of 80.7%. This makes it a fairly average month of the year for humidity in Singapore. 

Note that humidity is generally at its highest in the morning just before sunrise and at its lowest in the mid-afternoon (on days when there is no rain). 

You will notice the humidity rising in the lead up to a thunderstorm and it will drop again following the rain.

What should I pack for Singapore in September?

As you can see from the above statistics, Singapore is hot and humid in September and despite it being a relatively dry month, you should be always prepared for thunderstorms in both the mornings and afternoons. 

We recommend packing lightweight cotton clothing and carrying an umbrella and water bottle with you at all times. Also don’t forget your sunscreen, insect repellent and swimwear for when you want to jump in the pool to cool off. 

Click here for a more comprehensive guide to what to pack for Singapore. 

Anything else I need to know about visiting Singapore in September?

One of the biggest events of the year takes place in Singapore in September: The Singapore Grand Prix, Formula 1’s inaugural night race, which takes place around the Marina Bay circuit.

This fun and fabulous weekend is not only for racing fans, but also attracts some of the world’s biggest names in music too, in one of Asia’s largest music festivals. You can expect hotels to be busier than normal, and room rates to be higher during this weekend.

The Chinese Mid-Autumn Festival falls annually on the 15th day of the 8th lunar month. This is sometimes September and sometimes early October.

It’s a great time to head to Chinatown in the evening to admire all the lanterns. Also don’t miss out on trying a delicious range of mooncakes that are available all over town. 

Before you go… Don’t miss this all this useful information about visiting Singapore:

Click here to read more about the weather in Singapore in August and October.