☀️ Yes! Average temperature: 29°C
Yes! Average temperatures of 29°C make it pleasantly warm and ideal for sun-seekers. Koh Samui in September has an average air temperature of 29°C with sea temperatures around 28°C. You can expect 6 hours of sunshine per day and 120mm of rainfall, which means moderate rainfall — some wet days expected.
At 28°C the sea is like a warm bath — perfect for swimming, snorkelling, and diving. With 6 hours of daily sunshine, there's plenty of time to enjoy outdoor activities. Bring summer clothes, sunscreen, sunglasses, and a light cardigan for air-conditioned venues.
Koh Samui is one of the top warm destinations for September holidays from the UK. The average flight time from the UK is comfortable and there are usually good deals available for this time of year.
Here's how Koh Samui stacks up against similar destinations in September:
| Destination | Air °C | Sea °C | Rain | Sun |
|---|---|---|---|---|
| Koh Samui | 29°C | 28°C | 120mm | 6h |
| Belize | 29°C | 29°C | 170mm | 7h |
| Cyprus | 29°C | 27°C | 5mm | 11h |
| Palau | 29°C | 29°C | 280mm | 5h |
| Sri Lanka | 29°C | 27°C | 120mm | 7h |
| Antigua | 30°C | 29°C | 100mm | 8h |
See how Koh Samui's temperature changes throughout the year:
Looking for somewhere warm in September? These destinations are all 25°C+:
Yes, Koh Samui in September has average temperatures of 29°C, making it a warm destination. Sea temperatures are 28°C.
Yes, the sea temperature of 28°C is very comfortable for swimming.
Bring summer clothes, sunscreen, sunglasses, and a light cardigan for air-conditioned venues.
September is an excellent time to visit Koh Samui with warm weather and 6 hours of daily sunshine.
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