Ko Samui
September
Weather in Ko Samui for September 2025
Your guide to Ko Samui weather in September - trends and predictions
In general, the average temperature in Ko Samui at the beginning of September is 29 °C. As the month progressed, temperatures tended to slightly decrease, reaching an average of 28.7 °C by the end of September.
Ko Samui experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 157.1 mm.
Is September a good time to visit Ko Samui? check out the best time to travel to Ko Samui page.
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Temperatures
Rain 🌧️
More
1
Dry days
29
Rainy days
0
Snow days
28°/27°
Temperatures
25 km/h
Avg max wind
74 %
Avg humidity
Ko Samui in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  29° | 2 29° | 3  29° | 4 29° | 5  29° | 6 29° | 7  29° |
| 8 29° | 9 29° | 10 29° | 11 29° | 12 29° | 13 29° | 14 28° |
| 15 28° | 16  29° | 17 29° | 18 30° | 19 29° | 20 29° | 21 29° |
| 22 29° | 23 29° | 24 29° | 25 29° | 26 28° | 27 28° | 28 29° |
| 29 29° | 30 29° |
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Temperatures trend during September in Ko Samui
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Moderate or heavy rain shower | 29° /26° | 9.7 mm | 6 | |
| 2 Sept. | Moderate or heavy rain shower | 29° /27° | 4.3 mm | 6 | |
| 3 Sept. | Light rain shower | 29° /25° | 4.3 mm | 6 | |
| 4 Sept. | Light rain shower | 29° /26° | 4.4 mm | 6 | |
| 5 Sept. | Cloudy | 29° /26° | 13.2 mm | 6 | |
| 6 Sept. | Light rain shower | 29° /26° | 5.9 mm | 6 | |
| 7 Sept. | Heavy rain at times | 29° /26° | 7.1 mm | 6 | |
| 8 Sept. | Moderate or heavy rain shower | 29° /27° | 2.8 mm | 6 | |
| 9 Sept. | Patchy rain possible | 29° /27° | 4.2 mm | 6 | |
| 10 Sept. | Heavy rain at times | 29° /27° | 4.1 mm | 6 | |
| 11 Sept. | Moderate rain at times | 29° /27° | 1.5 mm | 6 | |
| 12 Sept. | Patchy rain possible | 29° /27° | 0.7 mm | 6 | |
| 13 Sept. | Patchy rain possible | 29° /27° | 4.5 mm | 6 | |
| 14 Sept. | Moderate or heavy rain shower | 28° /26° | 7 mm | 6 | |
| 15 Sept. | Moderate or heavy rain shower | 28° /26° | 5.1 mm | 6 | |
| 16 Sept. | Overcast | 29° /26° | 2.5 mm | 6 | |
| 17 Sept. | Patchy rain possible | 29° /27° | 1.7 mm | 7 | |
| 18 Sept. | Patchy rain possible | 30° /27° | 3.1 mm | 6 | |
| 19 Sept. | Moderate rain at times | 29° /27° | 3.8 mm | 6 | |
| 20 Sept. | Patchy rain possible | 29° /27° | 2.8 mm | 6 | |
| 21 Sept. | Moderate or heavy rain shower | 29° /27° | 7.8 mm | 6 | |
| 22 Sept. | Moderate or heavy rain shower | 29° /26° | 5.4 mm | 6 | |
| 23 Sept. | Cloudy | 29° /27° | 5.1 mm | 6 | |
| 24 Sept. | Light rain shower | 29° /27° | 7.2 mm | 6 | |
| 25 Sept. | Heavy rain at times | 29° /26° | 6.2 mm | 6 | |
| 26 Sept. | Moderate or heavy rain shower | 28° /26° | 8.3 mm | 6 | |
| 27 Sept. | Moderate or heavy rain shower | 28° /26° | 6.2 mm | 6 | |
| 28 Sept. | Moderate or heavy rain shower | 29° /26° | 7 mm | 6 | |
| 29 Sept. | Moderate or heavy rain shower | 29° /26° | 7.5 mm | 7 | |
| 30 Sept. | Patchy rain possible | 29° /27° | 3.6 mm | 6 | |
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Important Notice
Our weather forecast for Ko Samui in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Ko Samui forecast closer to your planned date for the most up-to-date weather information.
Ko Samui in September - FAQ
What are the expected maximum and minimum temperatures in Ko Samui during September?
During September, expect a variety of temperatures with highs around 28° and lows near 27°, suitable for diverse activities and preferences.
How much rainfall should be expected in Ko Samui during September?
Significant rainfall exceeding 157.1 mm is expected in Ko Samui during September, occurring over more than 29 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Ko Samui during September?
The average wind speed in Ko Samui during September is 25 km/h, suggesting breezy to windy conditions, depending on your activities.
What to pack to Ko Samui in September?
As you prepare for your trip to Ko Samui in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in Ko Samui, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Lightweight Clothing: T-shirts, blouses, shorts, skirts
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm weather
- Umbrellas/Raincoats: For rainy days
- Personal Items
- Sunscreen: High SPF for sunny destinations
- Lip Balm with SPF: To protect against chapped lips
September rainfall patterns in Ko Samui
Explore the daily rainfall trends and prepare for Ko Samuis September weather 💧
UV exposure in Ko Samui during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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