Tainan weather by month
Tainan runs from about 18°C in January to 29°C in July, with July the wettest month at 496 mm.
warmest month
July
29°C
coolest month
January
18°C
wettest month
July
496 mm
worst air month
October
37 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 18°C | 6 mm | 303 h | 26 |
| February | 20°C | 29 mm | 306 h | 28 |
| March | 22°C | 40 mm | 314 h | 32 |
| April | 27°C | 111 mm | 318 h | 28 |
| May | 27°C | 149 mm | 276 h | 28 |
| June | 28°C | 185 mm | 334 h | 20 |
| July | 29°C | 496 mm | 331 h | 20 |
| August | 28°C | 283 mm | 317 h | 25 |
| September | 28°C | 357 mm | 292 h | 30 |
| October | 26°C | 476 mm | 275 h | 37 |
| November | 23°C | 160 mm | 265 h | 33 |
| December | 19°C | 22 mm | 243 h | 28 |
About 3,574 hours of sun a year. Roughly 189 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.