Koh Tao weather by month
Koh Tao runs from about 27°C in December to 29°C in May, with October the wettest month at 325 mm.
warmest month
May
29°C
coolest month
December
27°C
wettest month
October
325 mm
worst air month
January
14 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 27°C | 40 mm | 337 h | 14 |
| February | 27°C | 30 mm | 319 h | 13 |
| March | 28°C | 5 mm | 343 h | 14 |
| April | 29°C | 10 mm | 352 h | 12 |
| May | 29°C | 129 mm | 335 h | 6 |
| June | 28°C | 145 mm | 256 h | 5 |
| July | 27°C | 199 mm | 221 h | 8 |
| August | 27°C | 227 mm | 292 h | 6 |
| September | 27°C | 160 mm | 255 h | 5 |
| October | 27°C | 325 mm | 305 h | 6 |
| November | 27°C | 278 mm | 251 h | 11 |
| December | 27°C | 267 mm | 265 h | 12 |
About 3,531 hours of sun a year. Roughly 181 rainy days a year.
These are long-run climate normals, not a forecast. A given year can sit well outside them. PM2.5 is a global model: near the coast it counts sea salt as fine particulate and reads high against ground stations, sometimes by a factor of two. Use the shape of the year, not the absolute number.
where these numbers come from
- · Temperature, rainfall and sunshine: ECMWF ERA5 reanalysis climate normals via Open-Meteo (CC BY 4.0), fetched once and stored.
- · PM2.5: Copernicus CAMS reanalysis, monthly means. Modelled, not station readings; near coasts CAMS counts sea salt as PM2.5 and reads high.
Last reviewed 2026-05-24. Full method, licences and the list of sources we rejected are on the methodology page.