Milan or Rio de Janeiro: which climate?
Milan (Italy) has a humid subtropical climate, whereas Rio de Janeiro (Brazil) has a tropical monsoon 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 Rio de Janeiro.
Rio de Janeiro is warmer than Milan by 10.2 °C in annual average: 23.4 °C against 13.2 °C.
Rio de Janeiro gets more rain than Milan: 1,270 mm per year against 1,146 mm.
Milan has warmed by +3.2 °C between 1940 and 2025, against +1.5 °C in Rio de Janeiro. Milan is therefore warming faster than Rio de Janeiro. Both trends are statistically significant.
Milan averages 28 hot days (≥ 30 °C) and 46 frost days per year; Rio de Janeiro averages 57 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 | Milan | Rio de Janeiro | Difference |
|---|---|---|---|
| Mean daily temperature | 13.2 °C | 23.4 °C | +10.2 °C |
| Average daily high | 17.6 °C | 26.5 °C | +8.9 °C |
| Average daily low | 9.3 °C | 20.9 °C | +11.6 °C |
| Annual rainfall | 1,146 mm | 1,270 mm | +124 mm |
| Sunshine / day | 9.3 h | 9.6 h | negligible |
| Hot days (≥ 30 °C) | 28 d/yr | 57 d/yr | +29 d/yr |
| Frost days (< 0 °C) | 46 d/yr | 0 d/yr | -46 d/yr |
| Rainy days (≥ 1 mm) | 115 d/yr | 157 d/yr | +42 d/yr |
| Mean relative humidity | 73 % | 81 % | +8 % |
| Average peak wind | 9.9 km/h | 16.9 km/h | +7.0 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.