Thailand (Koh Samui) · September
Low seasonThailand · Asia
Climate Overview
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
MAXMAX | 31° | 31° | 32° | 33° | 34° | 33° | 33° | 33° | 33° | 32° | 31° | 31° |
MINMIN | 26° | 26° | 27° | 27° | 27° | 27° | 27° | 27° | 27° | 26° | 26° | 26° |
☀️Sunshine | 8h UV 8 | 9h UV 9 | 10h UV 9 | 9h UV 9 | 8h UV 9 | 8h UV 8 | 7h UV 8 | 8h UV 8 | 6h UV 8 | 6h UV 7 | 6h UV 7 | 7h UV 7 |
🌊Water Temp | 28° | 29° | 30° | 31° | 31° | 30° | 30° | 30° | 30° | 30° | 29° | 28° |
🌧Rain Days | 8d154mm | 4d66mm | 4d112mm | 6d101mm | 11d152mm | 10d120mm | 11d142mm | 8d95mm | 11d122mm | 15d239mm | 16d474mm | 11d310mm |
Best travel time current monthMonthly averages 2005–2025 · Source: ERA5 + station data
Post-season — prices falling after the travel period, beaches and attractions quieter.
September in Thailand (Koh Samui) is generally manageable, but with 11 rain days it's not a reliably sunny month. Better conditions can be found in February, March, April, and August.
Daytime highs reach 32°C with a daily average of 29°C — nights stay warm at 26°C. The sun shines an average of 6 hours per day; there are 11 rain days with 122 mm total. The water is a warm 29°C — perfect for snorkelling and swimming.
A jacket for cool evenings should not be left behind. Sightseeing and excursions can be enjoyed at this time of year without the heat.
Packing list for Thailand (Koh Samui) in September
- Leichte Sommersachen
- Badezeug und Strandtuch
- Sonnencreme
- Sonnenbrille
- Leichter Regenschirm oder Regenponcho
- Insektenschutzmittel
- Reiseapotheke
Frequently Asked Questions
- Is September a good time to visit Thailand (Koh Samui)?
- September is not an optimal month for Thailand (Koh Samui) (Score: 60/100), but it is manageable. For better conditions, consider February, March, April, and August.
- How warm is it in Thailand (Koh Samui) in September?
- In September, Thailand (Koh Samui) sees daily highs of 32°C. Nights cool to 26°C, with a daily average of 29°C.
- How much rain falls in Thailand (Koh Samui) in September?
- In September, Thailand (Koh Samui) receives an average of 122 mm of rain over 11 rain days. An umbrella may occasionally be needed.
- How many sunshine hours does Thailand (Koh Samui) get in September?
- Thailand (Koh Samui) averages 6 sunshine hours per day in September — below the annual average.
- How warm is the water in Thailand (Koh Samui) in September?
- Water temperature in Thailand (Koh Samui) in September averages 29°C — ideal for swimming and snorkelling.
