Sapa weather by month
Sapa runs from about 11°C in December to 22°C in April, with September the wettest month at 679 mm.
warmest month
April
22°C
coolest month
December
11°C
wettest month
September
679 mm
worst air month
April
50 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 11°C | 182 mm | 188 h | 31 |
| February | 14°C | 19 mm | 259 h | 26 |
| March | 16°C | 89 mm | 260 h | 38 |
| April | 22°C | 23 mm | 330 h | 50 |
| May | 20°C | 292 mm | 276 h | 15 |
| June | 21°C | 270 mm | 217 h | 10 |
| July | 21°C | 283 mm | 294 h | 11 |
| August | 21°C | 335 mm | 249 h | 12 |
| September | 20°C | 679 mm | 258 h | 13 |
| October | 18°C | 124 mm | 298 h | 18 |
| November | 15°C | 65 mm | 243 h | 17 |
| December | 11°C | 102 mm | 136 h | 32 |
About 3,008 hours of sun a year. Roughly 204 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.