Koh Samui Weather Forecast
Koh Samui weather: 79°F, partly cloudy. Hourly forecast, 14-day outlook, UV, air quality and the best time to visit.
14-day forecast for Koh Samui
Daily highs and lows, precipitation and UV.
| Day | Conditions | High / Low | Precip | Wind | UV |
|---|---|---|---|---|---|
| Tue, Aug 25 | 🌦️ Drizzle | 81° / 75° | 67% · 0,1 in | 13 mph | 9 |
| Wed, Aug 26 | 🌦️ Light drizzle | 86° / 75° | 38% · 0,0 in | 17 mph | 9 |
| Thu, Aug 27 | ⛈️ Thunderstorm | 83° / 74° | 80% · 0,3 in | 15 mph | 9 |
| Fri, Aug 28 | 🌧️ Showers | 83° / 73° | 83% · 0,4 in | 14 mph | 9 |
| Sat, Aug 29 | 🌦️ Light showers | 80° / 73° | 75% · 0,5 in | 14 mph | 9 |
| Sun, Aug 30 | 🌦️ Drizzle | 79° / 72° | 78% · 0,2 in | 14 mph | 8 |
| Mon, Aug 31 | 🌦️ Light drizzle | 82° / 74° | 71% · 0,1 in | 11 mph | 8 |
| Tue, Sep 1 | 🌦️ Light drizzle | 83° / 74° | 63% · 0,1 in | 10 mph | 8 |
| Wed, Sep 2 | ⛈️ Thunderstorm | 84° / 74° | 86% · 0,3 in | 14 mph | 9 |
| Thu, Sep 3 | 🌦️ Drizzle | 80° / 74° | 80% · 0,2 in | 11 mph | 9 |
| Fri, Sep 4 | 🌦️ Light drizzle | 82° / 73° | 59% · 0,1 in | 11 mph | 2 |
| Sat, Sep 5 | 🌦️ Light drizzle | 82° / 75° | 53% · 0,0 in | 10 mph | 8 |
| Sun, Sep 6 | 🌦️ Light drizzle | 82° / 75° | 69% · 0,1 in | 11 mph | 9 |
| Mon, Sep 7 | 🌦️ Light drizzle | 84° / 75° | 75% · 0,1 in | 10 mph | 7 |
The two-week trend
Steady. The second week averages within a degree of the first, so no big change is signalled.
The window averages 82°F against a August normal of 84°F - right on average.
Rainfall over the next 7 days is close to normal for August (1,4 in against a typical 0,9 in).
What this means for Koh Samui
Today is about average for August. The forecast high of 81°F is in line with the 84°F typical for this month.
A 67% chance means rain is expected over most of the area. Plan indoor alternatives.
Gusts to 37 mph will push high-sided vehicles on exposed roads and bridges. Wet roads are likely; braking distances roughly double in heavy rain.
Within 15 degrees of the equator, day length barely changes all year; seasons are defined by rain, not temperature.
Northern Hemisphere, so peak summer falls in June to August.
The gap between the warmest and coldest month averages 37°F - an unusually even climate through the year.
What to pack, what to skip
- Lightweight, light-coloured clothing and a refillable water bottle
- Sunglasses, a brimmed hat and SPF 30+
- A packable rain shell - 6 of the next 7 days carry a real chance of rain
- Avoid exposed ridgelines, small boats and rooftop viewpoints while gusts stay above 37 mph.
- If your dates are flexible, avoid October, November and December - historically the least comfortable months here.
See the Koh Samui forecast by time range
Koh Samui weather - more answers
Explore Koh Samui
Every topic we hold for this place, and the same topic for the places around it.
Weather for related places
Frequently asked questions
Where is Koh Samui?
Koh Samui is an island in Thailand. Its coordinates are 9.512, 100.0136. It lies in Asia.
What is the weather like in Koh Samui right now?
It is currently 79°F (26°C) with partly cloudy. Humidity is 78% and wind is 10 mph.
When is the best time to visit Koh Samui?
January, February, March and April offer the most comfortable conditions in Koh Samui, which has a temperate climate. October, November and December are usually the hardest months for outdoor plans.
What time zone is Koh Samui in?
Koh Samui observes Asia/Bangkok (UTC+07:00). The local time is 3:47 PM.
What is the nearest airport to Koh Samui?
The closest airports are Phuket International Airport (HKT), 151 mi away and Suvarnabhumi Airport (BKK), 293 mi away.
What are the top things to do in Koh Samui?
Popular options include Khao Sok National Park, Railay Beach, Maya Bay, Phuket and Langkawi.
Related articles
Data sources and methodology
| Place data | USPOTUS Atlas dataset (islands) - coordinates, hierarchy and facts. |
|---|---|
| Forecast and observations | Open-Meteo (ECMWF and national models). |
| Air quality and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| Climate averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Method | Scores, comparisons and advice on this page are computed from the inputs above. Distances are straight-line. Nothing is estimated where data is missing - the block is simply not shown. |
Last updated August 25, 2026 at 3:47 PM local time. Live blocks refresh every 15 minutes; climate averages monthly.
