Cologne weather by month
Cologne runs from about 3°C in January to 21°C in August, with May the wettest month at 154 mm.
warmest month
August
21°C
coolest month
January
3°C
wettest month
May
154 mm
worst air month
March
15 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 3°C | 76 mm | 130 h | 15 |
| February | 8°C | 108 mm | 107 h | 11 |
| March | 9°C | 85 mm | 204 h | 15 |
| April | 11°C | 95 mm | 226 h | 11 |
| May | 15°C | 154 mm | 308 h | 8 |
| June | 17°C | 123 mm | 316 h | 8 |
| July | 19°C | 78 mm | 345 h | 8 |
| August | 21°C | 70 mm | 338 h | 8 |
| September | 16°C | 114 mm | 284 h | 7 |
| October | 13°C | 93 mm | 175 h | 10 |
| November | 7°C | 72 mm | 98 h | 11 |
| December | 5°C | 73 mm | 86 h | 14 |
About 2,617 hours of sun a year. Roughly 114 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.