Oslo weather by month
Oslo runs from about -8°C in January to 16°C in July, with July the wettest month at 186 mm.
warmest month
July
16°C
coolest month
January
-8°C
wettest month
July
186 mm
worst air month
February
13 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | -8°C | 91 mm | 80 h | 10 |
| February | -3°C | 91 mm | 91 h | 13 |
| March | 2°C | 86 mm | 133 h | 12 |
| April | 5°C | 61 mm | 288 h | 7 |
| May | 15°C | 78 mm | 431 h | 6 |
| June | 15°C | 138 mm | 408 h | 5 |
| July | 16°C | 186 mm | 328 h | 6 |
| August | 16°C | 122 mm | 309 h | 5 |
| September | 12°C | 107 mm | 227 h | 6 |
| October | 8°C | 64 mm | 146 h | 7 |
| November | 2°C | 30 mm | 110 h | 10 |
| December | 0°C | 53 mm | 66 h | 11 |
About 2,617 hours of sun a year. Roughly 111 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 2026-05-23. Full method, licences and the list of sources we rejected are on the methodology page.