Reference Data in Istanbul 17 indicators covering reference data for Istanbul. IndicatorLatest Year10-yr change Rank Cooling and heating degree days - Cities and FUAs — Change in cooling 72.11 Degree days 2025 down 6.6% 247th Cooling and heating degree days - Cities and FUAs — Cooling degree -29.49 % change on previous year 2025 down 721.3% 10th Cooling and heating degree days - Cities and FUAs — Change in cooling -60.99 % change on previous year 2025 down 417.2% 5th Cooling and heating degree days - Cities and FUAs, annual growth rate -1.55 % change on previous year 2025 down 106.1% 10th Cooling and heating degree days - Cities and FUAs — Change in heating -5.41 % change on previous year 2025 down 108.2% 10th Cooling and heating degree days - Cities and FUAs — Change in heating -311.25 Degree days 2025 down 147.2% 633rd Cooling and heating degree days - Cities and FUAs 1,016 Degree days 2025 down 15.4% 877th Cooling and heating degree days - Cities and FUAs — Cooling degree 269.54 Degree days 2025 down 1.8% 424th Precipitation - Cities and FUAs — Change in extreme precipitation -1.11 Days per year 2024 down 3.1% 1099th Precipitation - Cities and FUAs — Extreme precipitation days 3.52 Days per year 2024 down 0.9% 909th Exposure to extreme precipitation — Annual precipitation change 23.87 Millimetres per year 2023 up 113.9% 324th Exposure to extreme temperature — Annual temperature change 1.61 Degrees celsius 2023 up 91.5% 220th Dependency ratio - Cities and FUAs 11.6 Percentage of population aged 15-64 years 2024 up 38.1% 1159th Wind threats - Cities and FUAs — Exposure to wind threats 0 Percentage of area 2023 — 271st Coastal flooding - Cities and FUAs — Built-up area exposure to 0.0405 Percentage of built-up area 2022 up 33.7% 210th Internet speed - Cities and FUAs — Uploading speed 67.5 Percentage of national value 2025 up 338.3% 23rd Internet speed - Cities and FUAs — Downloading speed 34.5 Percentage of national value 2025 up 143.0% 57th