Milan or Porto: which climate?
Milan (Italy) has a humid subtropical climate, whereas Porto (Portugal) has a warm-summer mediterranean 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 Milan and to Porto.
Porto is warmer than Milan by 1.6 °C in annual average: 14.8 °C against 13.2 °C.
Porto gets more rain than Milan: 1,278 mm per year against 1,146 mm.
Porto gets 10.0 hours of sunshine per day on average, against 9.3 hours in Milan.
Milan has warmed by +3.2 °C between 1940 and 2025, against +1.3 °C in Porto. Milan is therefore warming faster than Porto. Both trends are statistically significant.
Milan averages 28 hot days (≥ 30 °C) and 46 frost days per year; Porto averages 11 and 1.
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 | Milan | Porto | Difference |
|---|---|---|---|
| Mean daily temperature | 13.2 °C | 14.8 °C | +1.6 °C |
| Average daily high | 17.6 °C | 18.5 °C | +0.9 °C |
| Average daily low | 9.3 °C | 11.5 °C | +2.2 °C |
| Annual rainfall | 1,146 mm | 1,278 mm | +132 mm |
| Sunshine / day | 9.3 h | 10.0 h | +0.7 h |
| Hot days (≥ 30 °C) | 28 d/yr | 11 d/yr | -17 d/yr |
| Frost days (< 0 °C) | 46 d/yr | 1 d/yr | -45 d/yr |
| Rainy days (≥ 1 mm) | 115 d/yr | 120 d/yr | +5 d/yr |
| Mean relative humidity | 73 % | 79 % | +6 % |
| Average peak wind | 9.9 km/h | 17.4 km/h | +7.5 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.