Reference Data in Seoul 18 indicators covering reference data for Seoul. IndicatorLatest Year10-yr change Rank Cooling and heating degree days - Cities and FUAs — Cooling degree -23.57 % change on previous year 2025 down 234.3% 417th Cooling and heating degree days - Cities and FUAs — Change in cooling -49.61 % change on previous year 2025 down 114.2% 273rd Cooling and heating degree days - Cities and FUAs, annual growth rate 1.56 % change on previous year 2025 up 144.5% 379th Cooling and heating degree days - Cities and FUAs — Change in heating 12.39 % change on previous year 2025 up 129.6% 378th Cooling and heating degree days - Cities and FUAs — Cooling degree 316.09 Degree days 2025 up 17.6% 381st Cooling and heating degree days - Cities and FUAs — Change in cooling 99.03 Degree days 2025 up 91.7% 198th Cooling and heating degree days - Cities and FUAs 2,184 Degree days 2025 up 1.3% 311th Cooling and heating degree days - Cities and FUAs — Change in heating -237.37 Degree days 2025 up 10.5% 526th Precipitation - Cities and FUAs — Extreme precipitation days 15.72 Days per year 2024 up 24.9% 277th Precipitation - Cities and FUAs — Change in extreme precipitation -2.52 Days per year 2024 up 55.4% 1237th Dependency ratio - Cities and FUAs 23.2 Percentage of population aged 15-64 years 2023 up 71.9% 910th Wind threats - Cities and FUAs — Exposure to wind threats 9.58 Percentage of area 2023 — 206th Coastal flooding - Cities and FUAs — Built-up area exposure to 0.8968 Percentage of built-up area 2022 up 278.3% 112th Internet speed - Cities and FUAs — Uploading speed 2.6 Percentage of national value 2025 up 333.3% 658th Internet speed - Cities and FUAs — Downloading speed 3.2 Percentage of national value 2025 down 54.3% 760th Correction coefficients outside the European Union (Duty stations) 78.5 Index 2025 down 23.7% 97th Purchasing Power Parities outside the European Union (Duty stations) 1,250 Purchasing power standard (PPS) 2025 down 2.8% 21st Correction coefficients outside the European Union (Duty stations) 78.5 Index 2025 down 23.7% 98th