Lausanne weather by month
Lausanne runs from about 2°C in December to 21°C in August, with May the wettest month at 178 mm.
warmest month
August
21°C
coolest month
December
2°C
wettest month
May
178 mm
worst air month
March
13 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 3°C | 126 mm | 144 h | 8 |
| February | 6°C | 59 mm | 191 h | 7 |
| March | 7°C | 108 mm | 240 h | 13 |
| April | 9°C | 127 mm | 284 h | 9 |
| May | 13°C | 178 mm | 303 h | 6 |
| June | 17°C | 114 mm | 333 h | 6 |
| July | 20°C | 101 mm | 391 h | 5 |
| August | 21°C | 54 mm | 374 h | 8 |
| September | 15°C | 155 mm | 248 h | 5 |
| October | 12°C | 124 mm | 235 h | 9 |
| November | 7°C | 84 mm | 216 h | 8 |
| December | 2°C | 110 mm | 165 h | 11 |
About 3,124 hours of sun a year. Roughly 134 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.