Athens or Lyon: which climate?
Athens (Greece) has a hot-summer mediterranean climate, whereas Lyon (France) has a temperate oceanic 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 Athens and to Lyon.
Athens is warmer than Lyon by 6.2 °C in annual average: 17.5 °C against 11.3 °C.
Lyon gets more rain than Athens: 961 mm per year against 364 mm.
Athens gets 10.4 hours of sunshine per day on average, against 8.8 hours in Lyon.
Lyon has warmed by +2.5 °C between 1940 and 2025, against +1.6 °C in Athens. Lyon is therefore warming faster than Athens. Both trends are statistically significant.
Athens averages 85 hot days (≥ 30 °C) and 3 frost days per year; Lyon averages 14 and 54.
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 | Athens | Lyon | Difference |
|---|---|---|---|
| Mean daily temperature | 17.5 °C | 11.3 °C | -6.2 °C |
| Average daily high | 22.1 °C | 15.6 °C | -6.5 °C |
| Average daily low | 13.2 °C | 7.3 °C | -5.9 °C |
| Annual rainfall | 364 mm | 961 mm | +597 mm |
| Sunshine / day | 10.4 h | 8.8 h | -1.6 h |
| Hot days (≥ 30 °C) | 85 d/yr | 14 d/yr | -71 d/yr |
| Frost days (< 0 °C) | 3 d/yr | 54 d/yr | +51 d/yr |
| Rainy days (≥ 1 mm) | 59 d/yr | 141 d/yr | +82 d/yr |
| Mean relative humidity | 64 % | 75 % | +11 % |
| Average peak wind | 15.4 km/h | 14.9 km/h | negligible |
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.