Click on a day for an hourly weather forecast
The temperatures in Koh Samet during September are extremely high, between 27°C and hot as 30°C, drinking water regularly is advisable.
There’s going to be many days of rain during the month of September in Koh Samet.
Koh Samet should expect an average of 15 to 22 days of rain, so be sure to bring along a waterproof jacket to stay dry this month!
Our weather forecast can give you a great sense of what weather to expect in Koh Samet in September 2025.
If you’re planning to visit Koh Samet in the near future, we highly recommend that you review the 14 day weather forecast for Koh Samet before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 30° / 25° | 3 | 28 | 0 | 57 mm | Good | Koh Samet in January |
| February | 30° / 26° | 3 | 25 | 0 | 57 mm | Good | Koh Samet in February |
| March | 31° / 27° | 8 | 23 | 0 | 124 mm | Ok | Koh Samet in March |
| April | 31° / 28° | 11 | 19 | 0 | 163 mm | Ok | Koh Samet in April |
| May | 31° / 28° | 18 | 13 | 0 | 370 mm | Ok | Koh Samet in May |
| June | 30° / 28° | 21 | 9 | 0 | 605 mm | Ok | Koh Samet in June |
| July | 30° / 27° | 21 | 10 | 0 | 619 mm | Ok | Koh Samet in July |
| August | 30° / 27° | 20 | 11 | 0 | 585 mm | Ok | Koh Samet in August |
| September | 30° / 27° | 19 | 11 | 0 | 563 mm | Ok | Koh Samet in September |
| October | 30° / 27° | 17 | 14 | 0 | 460 mm | Ok | Koh Samet in October |
| November | 31° / 26° | 6 | 24 | 0 | 147 mm | Good | Koh Samet in November |
| December | 30° / 25° | 2 | 29 | 0 | 39 mm | Good | Koh Samet in December |