Thailand
Best time to visit Koh Samui
Based on 0 years of real historical weather data (2015–2026). Sunshine hours, rainfall, and temperature — week by week.
Planning a trip, an event, or a party in Koh Samui? Here's what to expect. Summers here run hot, and winters are cooler. For the best odds of good weather, aim for February, March and January. Days run hot, with up to 10.7h of sunshine and mostly dry.
Month-by-month weather
Koh Samui in January runs hot, averaging 25.1°C.
Koh Samui in February runs hot, averaging 25.7°C.
Koh Samui in March runs hot, averaging 27.1°C.
Koh Samui in April runs hot, averaging 28°C.
Koh Samui in May runs hot, averaging 28.2°C.
Koh Samui in June runs hot, averaging 28°C.
Koh Samui in July runs hot, averaging 27.9°C.
Koh Samui in August runs hot, averaging 28°C.
Koh Samui in September runs hot, averaging 26.9°C.
Koh Samui in October runs hot, averaging 26°C.
Koh Samui in November runs hot, averaging 25.6°C.
Koh Samui in December runs hot, averaging 25.2°C.
Frequently asked questions
What is the best time to visit Koh Samui?
If you're planning a trip, wedding, or outdoor event in Koh Samui, aim for February, March and January — Days run hot, with up to 10.7h of sunshine and mostly dry. This is based on 0 years of real historical weather data (2015–2026), not a single forecast.
What is the weather like in Koh Samui in February?
If you visit Koh Samui in February, expect hot days around 25.7°C You'll get around 10.7h of sunshine per day and 1.7mm of rain — mostly dry.
What is the hottest month in Koh Samui?
May is typically the hottest month, running hot — good to know if you're planning something outdoors and want to avoid the peak heat.
What is the driest month in Koh Samui?
February is your safest bet if you want to avoid rain, averaging only 1.7mm per day. November is the wettest, at 9.7mm per day — worth planning around if you're hosting anything outdoors.
All weeks ranked by weather score
| Week | Dates | Midday temp | Range | Sun / day | Rain / day | Score |
|---|---|---|---|---|---|---|
| W6 | Feb 5–11 | 25.5°C | 20.8° → 26.3° | 11.0h | 1.0mm | 83 |
| W7 | Feb 12–18 | 25.7°C | 21.5° → 26.5° | 10.9h | 1.6mm | 81 |
| W9 | Feb 26–Mar 3 | 26.0°C | 22° → 26.7° | 10.9h | 1.4mm | 80 |
| W10 | Mar 4–10 | 26.6°C | 21.7° → 27.2° | 10.9h | 1.2mm | 79 |
| W11 | Mar 11–17 | 27.1°C | 22° → 27.6° | 11.1h | 0.8mm | 79 |
| W5 | Jan 29–Feb 4 | 25.3°C | 21.3° → 26.1° | 10.5h | 1.9mm | 78 |
| W2 | Jan 8–14 | 25.2°C | 21.4° → 25.9° | 10.6h | 2.2mm | 77 |
| W4 | Jan 22–28 | 25.1°C | 20.7° → 25.8° | 10.5h | 2.3mm | 77 |
| W51 | Dec 16–22 | 25.2°C | 21.6° → 26.2° | 10.3h | 2.4mm | 77 |
| W8 | Feb 19–25 | 25.8°C | 21.7° → 26.5° | 10.0h | 2.4mm | 76 |
| W12 | Mar 18–24 | 27.5°C | 22.4° → 28.4° | 11.2h | 1.4mm | 75 |
| W15 | Apr 8–14 | 28.3°C | 23.4° → 29.1° | 11.6h | 1.3mm | 74 |
| W33 | Aug 12–18 | 28.1°C | 23.4° → 28.8° | 10.5h | 1.4mm | 74 |
| W28 | Jul 8–14 | 27.9°C | 23.2° → 28.9° | 9.9h | 1.7mm | 73 |
| W52 | Dec 23–29 | 25.3°C | 21.3° → 26° | 9.7h | 3.3mm | 72 |
| W3 | Jan 15–21 | 25.2°C | 21.2° → 25.9° | 10.0h | 3.7mm | 71 |
| W26 | Jun 24–30 | 28.2°C | 23.2° → 29.1° | 9.9h | 2.1mm | 70 |
| W31 | Jul 29–Aug 4 | 27.9°C | 23.4° → 28.9° | 9.4h | 2.0mm | 70 |
| W32 | Aug 5–11 | 27.9°C | 23.1° → 29° | 9.1h | 2.2mm | 70 |
| W34 | Aug 19–25 | 28.3°C | 23.1° → 29.3° | 10.1h | 2.1mm | 70 |
| W16 | Apr 15–21 | 28.3°C | 23.6° → 29.2° | 11.5h | 2.4mm | 69 |
| W13 | Mar 25–31 | 27.2°C | 22.3° → 28.1° | 10.4h | 3.3mm | 68 |
| W24 | Jun 10–16 | 28.2°C | 23.3° → 29.3° | 10.5h | 2.7mm | 67 |
| W27 | Jul 1–7 | 28.3°C | 23.4° → 29.3° | 9.2h | 2.4mm | 67 |
| W17 | Apr 22–28 | 28.4°C | 23.5° → 29.4° | 11.2h | 2.6mm | 66 |
| W19 | May 6–12 | 28.4°C | 23.6° → 29.4° | 11.2h | 2.6mm | 66 |
| W23 | Jun 3–9 | 27.8°C | 23.5° → 29° | 9.9h | 2.9mm | 66 |
| W25 | Jun 17–23 | 27.9°C | 22.9° → 28.9° | 9.5h | 2.9mm | 66 |
| W30 | Jul 22–28 | 27.7°C | 22.7° → 28.6° | 9.9h | 3.2mm | 66 |
| W22 | May 27–Jun 2 | 27.8°C | 23.4° → 28.7° | 10.2h | 3.0mm | 65 |
| W35 | Aug 26–Sep 1 | 27.8°C | 22.7° → 28.9° | 9.9h | 3.3mm | 65 |
| W21 | May 20–26 | 28.4°C | 23.3° → 29.4° | 9.9h | 3.4mm | 63 |
| W20 | May 13–19 | 28.4°C | 23.3° → 29.2° | 10.7h | 3.4mm | 62 |
| W50 | Dec 9–15 | 25.4°C | 21.6° → 26.1° | 10.3h | 6.3mm | 61 |
| W41 | Oct 7–13 | 26.2°C | 21.9° → 26.9° | 10.1h | 4.7mm | 60 |
| W36 | Sep 2–8 | 27.3°C | 22.7° → 28.3° | 8.4h | 3.8mm | 59 |
| W37 | Sep 9–15 | 27.2°C | 22.6° → 28.4° | 8.7h | 4.6mm | 58 |
| W47 | Nov 18–24 | 25.9°C | 21.6° → 26.6° | 9.5h | 6.2mm | 58 |
| W29 | Jul 15–21 | 27.6°C | 22.7° → 28.8° | 9.0h | 4.7mm | 57 |
| W18 | Apr 29–May 5 | 27.9°C | 23.2° → 29.2° | 10.8h | 4.9mm | 56 |
| W39 | Sep 23–29 | 26.6°C | 22.4° → 27.4° | 9.1h | 5.7mm | 56 |
| W1 | Jan 1–7 | 24.8°C | 21.4° → 25.6° | 8.9h | 15.6mm | 53 |
| W46 | Nov 11–17 | 25.5°C | 21.7° → 26.4° | 9.4h | 8.8mm | 53 |
| W14 | Apr 1–7 | 27.2°C | 22.5° → 28.4° | 10.0h | 8.3mm | 52 |
| W43 | Oct 21–27 | 26.0°C | 21.6° → 26.7° | 9.3h | 7.4mm | 52 |
| W38 | Sep 16–22 | 26.6°C | 22.1° → 27.9° | 7.9h | 6.7mm | 51 |
| W49 | Dec 2–8 | 24.9°C | 21.6° → 26° | 8.5h | 12.6mm | 50 |
| W40 | Sep 30–Oct 6 | 26.1°C | 22.3° → 27.3° | 8.1h | 7.6mm | 49 |
| W42 | Oct 14–20 | 26.0°C | 21.8° → 26.9° | 8.4h | 7.9mm | 49 |
| W44 | Oct 28–Nov 3 | 25.7°C | 21.7° → 26.9° | 8.9h | 9.9mm | 49 |
| W48 | Nov 25–Dec 1 | 25.4°C | 21.6° → 26.4° | 8.0h | 12.9mm | 47 |
| W45 | Nov 4–10 | 25.5°C | 21.6° → 26.3° | 8.0h | 11.0mm | 45 |
Nail down the right dates for Koh Samui
Compare individual weeks, see year-by-year variation, and download the data as Excel — everything you need to plan a trip, wedding, or event.
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