Lyon or Milan: which climate?
Lyon (France) has a temperate oceanic climate, whereas Milan (Italy) has a humid subtropical 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 Lyon and to Milan.
Milan is warmer than Lyon by 1.9 °C in annual average: 13.2 °C against 11.3 °C.
Milan gets more rain than Lyon: 1,146 mm per year against 961 mm.
Milan gets 9.3 hours of sunshine per day on average, against 8.8 hours in Lyon.
Milan has warmed by +3.2 °C between 1940 and 2025, against +2.5 °C in Lyon. Milan is therefore warming faster than Lyon. Both trends are statistically significant.
Lyon averages 14 hot days (≥ 30 °C) and 54 frost days per year; Milan averages 28 and 46.
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 | Lyon | Milan | Difference |
|---|---|---|---|
| Mean daily temperature | 11.3 °C | 13.2 °C | +1.9 °C |
| Average daily high | 15.6 °C | 17.6 °C | +2.0 °C |
| Average daily low | 7.3 °C | 9.3 °C | +2.0 °C |
| Annual rainfall | 961 mm | 1,146 mm | +185 mm |
| Sunshine / day | 8.8 h | 9.3 h | +0.5 h |
| Hot days (≥ 30 °C) | 14 d/yr | 28 d/yr | +14 d/yr |
| Frost days (< 0 °C) | 54 d/yr | 46 d/yr | -8 d/yr |
| Rainy days (≥ 1 mm) | 141 d/yr | 115 d/yr | -26 d/yr |
| Mean relative humidity | 75 % | 73 % | negligible |
| Average peak wind | 14.9 km/h | 9.9 km/h | -5.0 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.