Istanbul or Milan: which climate?
Istanbul (Republic of Türkiye) has a hot-summer mediterranean 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 Istanbul and to Milan.
Istanbul is warmer than Milan by 1.3 °C in annual average: 14.5 °C against 13.2 °C.
Milan gets more rain than Istanbul: 1,146 mm per year against 697 mm.
Milan has warmed by +3.2 °C between 1940 and 2025, against +1.6 °C in Istanbul. Milan is therefore warming faster than Istanbul. Both trends are statistically significant.
Istanbul averages 3 hot days (≥ 30 °C) and 5 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 | Istanbul | Milan | Difference |
|---|---|---|---|
| Mean daily temperature | 14.5 °C | 13.2 °C | -1.3 °C |
| Average daily high | 16.8 °C | 17.6 °C | +0.8 °C |
| Average daily low | 12.5 °C | 9.3 °C | -3.2 °C |
| Annual rainfall | 697 mm | 1,146 mm | +449 mm |
| Sunshine / day | 9.5 h | 9.3 h | negligible |
| Hot days (≥ 30 °C) | 3 d/yr | 28 d/yr | +25 d/yr |
| Frost days (< 0 °C) | 5 d/yr | 46 d/yr | +41 d/yr |
| Rainy days (≥ 1 mm) | 105 d/yr | 115 d/yr | +10 d/yr |
| Mean relative humidity | 76 % | 73 % | -3 % |
| Average peak wind | 21.4 km/h | 9.9 km/h | -11.5 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.