Porto weather by month
Porto runs from about 11°C in December to 20°C in August, with March the wettest month at 287 mm.
warmest month
August
20°C
coolest month
December
11°C
wettest month
March
287 mm
worst air month
March
15 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 12°C | 251 mm | 177 h | 10 |
| February | 13°C | 219 mm | 212 h | 12 |
| March | 12°C | 287 mm | 258 h | 15 |
| April | 15°C | 133 mm | 337 h | 14 |
| May | 15°C | 82 mm | 361 h | 11 |
| June | 18°C | 79 mm | 366 h | 9 |
| July | 20°C | 31 mm | 391 h | 9 |
| August | 20°C | 2 mm | 372 h | 14 |
| September | 18°C | 77 mm | 313 h | 10 |
| October | 17°C | 252 mm | 196 h | 14 |
| November | 16°C | 101 mm | 220 h | 11 |
| December | 11°C | 48 mm | 247 h | 14 |
About 3,450 hours of sun a year. Roughly 156 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 2026-05-22. Full method, licences and the list of sources we rejected are on the methodology page.