Barcelona or Istanbul: which climate?
Barcelona (Spain) has a humid subtropical climate, whereas Istanbul (Republic of Türkiye) has a hot-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 Barcelona and to Istanbul.
Barcelona is warmer than Istanbul by 0.5 °C in annual average: 15.0 °C against 14.5 °C.
Istanbul gets more rain than Barcelona: 697 mm per year against 619 mm.
Barcelona gets 10.2 hours of sunshine per day on average, against 9.5 hours in Istanbul.
Barcelona has warmed by +2.0 °C between 1940 and 2025, against +1.6 °C in Istanbul. Barcelona is therefore warming faster than Istanbul. Both trends are statistically significant.
Barcelona averages 3 hot days (≥ 30 °C) and 2 frost days per year; Istanbul averages 3 and 5.
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 | Barcelona | Istanbul | Difference |
|---|---|---|---|
| Mean daily temperature | 15.0 °C | 14.5 °C | -0.5 °C |
| Average daily high | 18.5 °C | 16.8 °C | -1.7 °C |
| Average daily low | 12.0 °C | 12.5 °C | +0.5 °C |
| Annual rainfall | 619 mm | 697 mm | +78 mm |
| Sunshine / day | 10.2 h | 9.5 h | -0.7 h |
| Hot days (≥ 30 °C) | 3 d/yr | 3 d/yr | negligible |
| Frost days (< 0 °C) | 2 d/yr | 5 d/yr | negligible |
| Rainy days (≥ 1 mm) | 95 d/yr | 105 d/yr | +10 d/yr |
| Mean relative humidity | 78 % | 76 % | negligible |
| Average peak wind | 15.5 km/h | 21.4 km/h | +5.9 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.