Koh Samet Weather in September
During September, Koh Samet experiences very high daytime temperatures of 30°C (86°F) and cooler nights around 26°C (79°F). As the wettest month of the year, expect frequent rainfall.
Rainfall in Koh Samet in September
Koh Samet is in the rainy season in September, with rain on around 19 days and an average of 322 mm (13 in). Rainy season showers here are typically intense, often clearing quickly but coming down hard while they last.
Temperature in Koh Samet in September
September in Koh Samet brings typical temperatures with highs around 30°C (86°F) and lows of 26°C (79°F). It's usually most comfortable outside during the morning and later in the day. At 26°C (79°F) overnight, the heat doesn't let up much after dark. If you're staying somewhere without air conditioning, a cold shower before bed and keeping the air moving can help.
Sunshine in Koh Samet in September
The area experiences a moderate amount of sunshine, with approximately 110 hours of sunlight expected. Even though this month is part of the rainy season, you could still see the sun every now and then.If you're looking for dry conditions and comfortable temperatures, September may not be the ideal month to visit Koh Samet. Our weather planner can help you explore destinations with more pleasant weather conditions.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Thailand, check out our Koh Samet's climate page.
Koh Samet Temperature in September
Min Temperature
26°C (79°F)
Max Temperature
30°C (86°F)
Chance of Rain
62%
Precipitation
322 mm (13 in)
Rainy days
19 days
Humidity
81% *
Sunshine
110 hours *
Percentage Sunshine
*
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Koh Samet typically stay consistent throughout September, with daily highs averaging around 30°C (86°F). Nights are warm, with lows around 26°C (79°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Koh Samet in September
Browse day-by-day weather records for Koh Samet spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Koh Samet historical weather extremes in September
Our historical data for Koh Samet spans 1976 to 2025, revealing these weather extremes.
- Koh Samet recorded its highest September temperature of 38°C (100°F) on September 13, 1987.
- The lowest daytime temperature in September was 26°C (79°F), recorded on September 5, 1976.
- Koh Samet registered its coldest September night on September 11, 1995, with temperatures dropping to 22°C (72°F).
- The wettest September day on record brought 198 mm (7.8 in) of precipitation to Koh Samet (September 10, 1996).
Best Places in Thailand in September
Find out more about the weather in Thailand and which places have the best travel conditions in this month. See all of Thailand in September →
perfect weather
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tolerable
unpleasant
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What to Wear in Koh Samet in September
Warm but pleasant conditions in Koh Samet in September. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. It's going to pour! Pack a good poncho and prepare for very wet conditions. Bring sunglasses since you'll have some sunny periods throughout the monthWhat To Do in Koh Samet in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Thailand, check out our Koh Samet's climate page.
Temperature Rainfall Sunshine Humidity
See the full Koh Samet climate overview or explore weather in Thailand.
