Brussels or Geneva: which climate?
Brussels (Belgium) has a temperate oceanic climate, whereas Geneva (Switzerland) has a warm-summer humid continental climate, according to the Köppen-Geiger classification.
The values compared here are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme. The same method and the same period apply to Brussels and to Geneva.
Brussels is warmer than Geneva by 1.6 °C in annual average: 10.2 °C against 8.6 °C.
Geneva gets more rain than Brussels: 1,405 mm per year against 735 mm.
Geneva gets 8.9 hours of sunshine per day on average, against 7.6 hours in Brussels.
Geneva has warmed by +3.0 °C between 1940 and 2025, against +1.9 °C in Brussels. Geneva is therefore warming faster than Brussels. Both trends are statistically significant.
Brussels averages 3 hot days (≥ 30 °C) and 47 frost days per year; Geneva averages 2 and 100.
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
| Indicator | Brussels | Geneva | Difference |
|---|---|---|---|
| Mean daily temperature | 10.2 °C | 8.6 °C | -1.6 °C |
| Average daily high | 13.6 °C | 12.9 °C | -0.7 °C |
| Average daily low | 6.9 °C | 4.5 °C | -2.4 °C |
| Annual rainfall | 735 mm | 1,405 mm | +670 mm |
| Sunshine / day | 7.6 h | 8.9 h | +1.3 h |
| Hot days (≥ 30 °C) | 3 d/yr | 2 d/yr | negligible |
| Frost days (< 0 °C) | 47 d/yr | 100 d/yr | +53 d/yr |
| Rainy days (≥ 1 mm) | 144 d/yr | 161 d/yr | +17 d/yr |
| Mean relative humidity | 80 % | 78 % | negligible |
| Average peak wind | 19.9 km/h | 9.6 km/h | -10.3 km/h |
A difference is only reported when it exceeds the resolution of the data. ERA5 is a reanalysis on a grid of about 31 km: two nearby cities often fall in the same cell, and below half a degree you are reading the grid, not the climate.