Koh Samui in Summer — Weather & What to Expect
Summer in Koh Samui (June, July, August) averages daytime highs of 30.3°C and lows of 26.0°C, with around 366.5mm of rain across the season (61 rainy days in total). It includes some of the best months of the year to visit (June, July, August).
In the northern hemisphere, summer in Koh Samui covers June, July, August.
Summer in Koh Samui month by month
| Month | High | Low | Rain | Rainy days | Rating |
|---|---|---|---|---|---|
| June | 30.6°C | 26.2°C | 102.4mm | 18 | 9/10 |
| July | 30.0°C | 25.9°C | 149.9mm | 22 | 9/10 |
| August | 30.4°C | 26.0°C | 114.2mm | 21 | 9/10 |
What to pack for Koh Samui in summer
- Lightweight, breathable clothing
- High SPF sunscreen
- Sunglasses
- Sun hat
- Reusable water bottle
- Compact travel umbrella
- Waterproof jacket
- Quick-dry clothing
Frequently Asked Questions
Is summer a good time to visit Koh Samui?
Summer in Koh Samui rates around 9/10 — excellent time to visit. Average highs are 30.3°C with 366.5mm of rain across the season.
How hot is Koh Samui in summer?
Daytime highs average 30.3°C (86.5°F) across June, July, August, with nights around 26.0°C.
What months are summer in Koh Samui?
Koh Samui is in the northern hemisphere, so summer covers June, July, August.
See also: best time to visit Koh Samui · Koh Samui annual climate · Koh Samui in spring · Koh Samui in autumn · Koh Samui in winter
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Once you know what summer in Koh Samui looks like, find out exactly what to pack for Koh Samui at 247PackingList. For currency, language and country facts, see the Thailand guide at 247CountryInfo.
Summer in Koh Samui — what to pack
Lightweight travel clothing
Lightweight, breathable clothing and a compact travel umbrella are essential in this climate.
Check Price →Check clothing sizes in Thailand at 247Sizing before you shop.
More summer travel essentials
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Climate data sourced from Open-Meteo (open source, open data licence). Monthly averages calculated from 2020–2023 historical data. Weather can be unpredictable — always check a live forecast before travelling.