- Save EXTRA 10% on 18-29 trips worldwide
- Book online at least 9 months in advance to get discount
- Excludes Tailor-made, Asia passes, short breaks & 3rd parties
Ko Samui weather in September 2021
Get the latest coronavirus (Covid-19) updates for Thailand with current travel advice, vaccine statistics and online resources.
- 3131°C max day temperature
- 1717 days with some rainfall
- 2424°C min night temperature
- 1212 hours of daylight per day
- VHVery High heat & humidity
- 141141 mm of monthly rainfall
- 1111+ (Extreme) UV index
- 2929°C sea temperature
Recommended for Thailand
The September weather guide for Ko Samui, Thailand shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.
How hot is it in Ko Samui in September?
Daytime temperatures usually reach 31°C in Ko Samui in September with very high heat and humidity, falling to 24°C at night.
How sunny is it in Ko Samui in September?
There are normally 6 hours of bright sunshine each day in Ko Samui in September - that's 47% of daylight hours.
How warm is the sea around Ko Samui in September?
The average sea temperature around Ko Samui in September is 29°C.
Does it rain in Ko Samui in September?
There are usually 17 days with some rain in Ko Samui in September and the average monthly rainfall is 141mm.
Metric (°C / mm) | Imperial (°F / inches)
Ko Samui sunrise & sunset times for September 2021
Browse the sunrise and sunset times for Ko Samui in September 2021. Select a month to view Ko Samui sunrise & sunset times for the next 12 months.
|Date||Sunrise times||Sunset times|
|Wednesday, 1st September 2021||06:11||18:29|
|Wednesday, 15th September 2021||06:10||18:20|
|Thursday, 30th September 2021||06:08||18:11|
- Check out the low fares on flights to Thailand
- Finnair flights connect in Helsinki Airport, Finland
- Browse lowest fares available
Get your weekly fix of holiday inspiration from some of the world's best travel writers plus save on your next trip with the latest exclusive offers
We promise not to share your details
Popular travel offers
*affiliate links: find out how we are funded and why this helps us remain free to use.