San Marino weather by month
San Marino runs from about 3°C in December to 24°C in August, with October the wettest month at 183 mm.
warmest month
August
24°C
coolest month
December
3°C
wettest month
October
183 mm
worst air month
December
19 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 4°C | 95 mm | 188 h | 14 |
| February | 7°C | 52 mm | 204 h | 12 |
| March | 9°C | 81 mm | 250 h | 15 |
| April | 11°C | 75 mm | 318 h | 11 |
| May | 14°C | 101 mm | 364 h | 6 |
| June | 20°C | 49 mm | 389 h | 6 |
| July | 24°C | 45 mm | 431 h | 5 |
| August | 24°C | 37 mm | 379 h | 7 |
| September | 17°C | 177 mm | 266 h | 5 |
| October | 14°C | 183 mm | 189 h | 6 |
| November | 7°C | 43 mm | 204 h | 10 |
| December | 3°C | 98 mm | 182 h | 19 |
About 3,364 hours of sun a year. Roughly 105 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.