Koh Samui or Krabi in March?
On climate data, Koh Samui comes out ahead overall in March. See the per-criterion details below.
Koh SamuiPhoto: Sonia Selivonchik · CC BY-SA 4.0
KrabiPhoto: kallerna · CC BY-SA 3.0Key figures in March
| Criterion | Koh Samui | Krabi |
|---|---|---|
| Day | 29 °C | 31 °C ★ |
| Night | 27 °C ★ | 25 °C |
| Sea | 29 °C | 29 °C ★ |
| Rainy days | 6 rainy days | 6 rainy days |
| Sun | 8 h/day | 8 h/day ★ |
Winner by travel type
Koh Samui or Krabi in March: the short answer
In March, Koh Samui comes out ahead on the overall climate score (Koh Samui 80/100 vs Krabi 74/100). That is a snapshot of one month, though — which one truly fits depends on what you want from the trip, so the breakdown below goes criterion by criterion.
Across the whole year Koh Samui averages a climate score of 73/100, Krabi 67/100. Both profiles below are historical monthly averages, not a forecast.
Weather in March, side by side
By day, Koh Samui sits near 29 °C and Krabi near 31 °C — warmer in Krabi. At night it is roughly 27 °C versus 25 °C.
On rain, Koh Samui sees about 6 rainy days in March and Krabi about 6. Krabi gets more sunshine (8 vs 8 hours a day).
Sea temperature and swimming
In March the water is about 29 °C at Koh Samui and 29 °C at Krabi — warmer for swimming at Krabi. Over the year, Koh Samui is comfortable for swimming (from ~21 °C) in January, February, March, April, May, June, July, August, September, October, November and December, Krabi in January, February, March, April, May, June, July, August, September, October, November and December. Peak sea warmth is May for Koh Samui and May for Krabi.
Rain and sun across the year
Over a full year Koh Samui records roughly 118 rainy days and Krabi about 150 — the drier of the two overall is Koh Samui. At their sunniest, Koh Samui reaches about 8 hours of sun a day (March) and Krabi about 8 (March). If dependable dry, sunny weather is your top priority, weigh these annual totals alongside the single month above.
Best time to visit each
Climatically, Koh Samui is at its best in January, February, March and July, while Krabi peaks in January, February, March and December. If your dates are fixed, pick the destination whose strong season overlaps them; if you are flexible, plan around these windows.
Which suits which kind of trip
Based on the March scores for each travel style:
Beach & swimming: Koh Samui scores higher in March.
City breaks: Koh Samui scores higher in March.
Active & hiking: Koh Samui scores higher in March.
Family: Koh Samui scores higher in March.
Verdict: which should you pick?
There is no single winner — it depends on your month and your priority. For March specifically, use the head-to-head above; over the year, Koh Samui carries the slightly higher overall climate score. Choose Koh Samui if its strong months and profile match your plan, Krabi if its do. The month-by-month pages for each destination give you the full picture before you book.