Athens or Buenos Aires: which climate?
Athens (Greece) has a hot-summer mediterranean climate, whereas Buenos Aires (Argentina) 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 Athens and to Buenos Aires.
Athens and Buenos Aires have the same mean annual temperature, about 17.5 °C: the gap between the two cities is too small to be told apart from the noise in the data.
Buenos Aires gets more rain than Athens: 992 mm per year against 364 mm.
Athens gets 10.4 hours of sunshine per day on average, against 9.6 hours in Buenos Aires.
Athens has warmed by +1.6 °C between 1940 and 2025, against +0.6 °C in Buenos Aires. Athens is therefore warming faster than Buenos Aires. Both trends are statistically significant.
Athens averages 85 hot days (≥ 30 °C) and 3 frost days per year; Buenos Aires averages 11 and 0.
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 | Buenos Aires | Difference |
|---|---|---|---|
| Mean daily temperature | 17.5 °C | 17.2 °C | negligible |
| Average daily high | 22.1 °C | 20.4 °C | -1.7 °C |
| Average daily low | 13.2 °C | 14.2 °C | +1.0 °C |
| Annual rainfall | 364 mm | 992 mm | +628 mm |
| Sunshine / day | 10.4 h | 9.6 h | -0.8 h |
| Hot days (≥ 30 °C) | 85 d/yr | 11 d/yr | -74 d/yr |
| Frost days (< 0 °C) | 3 d/yr | 0 d/yr | negligible |
| Rainy days (≥ 1 mm) | 59 d/yr | 93 d/yr | +34 d/yr |
| Mean relative humidity | 64 % | 75 % | +11 % |
| Average peak wind | 15.4 km/h | 22.6 km/h | +7.2 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.