WEATHER · CLIMATE NORMALS · 1991–2020
Cologne Climate — Averages by Month
What the weather in Cologne, DEaverages across a standard 30-year period. Each month's figure is the 1991–2020 mean temperature and total rainfall from the ERA5 reanalysis — the long-run normal a place settles around, not a forecast for any particular day.
Month-by-month normals
| Month | Avg temperature | Avg rainfall |
|---|---|---|
| January | 2.8 °C · coldest | 96.9 mm |
| February | 3.4 °C | 80.7 mm |
| March | 6.4 °C | 79.1 mm |
| April | 10.2 °C | 57.5 mm |
| May | 14.0 °C | 68.0 mm |
| June | 17.0 °C | 76.2 mm |
| July | 19.0 °C · warmest | 86.3 mm |
| August | 18.7 °C | 85.5 mm |
| September | 14.9 °C | 76.1 mm |
| October | 10.8 °C | 88.6 mm |
| November | 6.5 °C | 91.6 mm |
| December | 3.6 °C | 107.9 mm · wettest |
How to read these numbers
These are reanalysis normals, not readings from a single weather station. They come from the ERA5 0.25° (~25 km) global reanalysis grid, sampled at the grid cell nearest Cologne — centred at 51.00°N, 7.00°E. A reanalysis blends observations with a physics model onto an even grid, so a coastal or mountain city's cell can read a little cooler, warmer, wetter or drier than the city centre itself. The month-to-month shape — when it's hot, when it rains — is what these normals capture best.
“Normal” means the 1991–2020 average, the current World Meteorological Organization standard period. A normal is what a place tends toward over decades — any single day, month or year can and will depart from it.