The weather in Koh Yao Yai in September is very hot. The average temperatures are between 24°C and 31°C, drinking water regularly is advisable.
There’s going to be many days of rain during the month of September in Koh Yao Yai.
Koh Yao Yai 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 Yao Yai in September 2025.
If you’re planning to visit Koh Yao Yai in the near future, we highly recommend that you review the 14 day weather forecast for Koh Yao Yai before you arrive.
Temperatures
31° / 24°
Rainy Days
16
Snowy Days
0
Dry Days
14
Rainfall
351
mm
Sun Hours
10.0
Hrs
