Reference Data in Jeju 18 indicators covering reference data for Jeju. IndicatorLatest Year10-yr change Rank Cooling and heating degree days - Cities and FUAs 1,144 Degree days 2025 down 3.0% 835th Cooling and heating degree days - Cities and FUAs — Cooling degree 0.3336 % change on previous year 2025 down 97.8% 85th Cooling and heating degree days - Cities and FUAs — Change in cooling 0.6633 % change on previous year 2025 down 97.9% 90th Cooling and heating degree days - Cities and FUAs, annual growth rate 8.77 % change on previous year 2025 up 365.4% 212th Cooling and heating degree days - Cities and FUAs — Change in heating 38.95 % change on previous year 2025 up 166.8% 254th Cooling and heating degree days - Cities and FUAs — Change in heating -144.51 Degree days 2025 down 32.1% 353rd Cooling and heating degree days - Cities and FUAs — Change in cooling 224.91 Degree days 2025 up 556.2% 38th Cooling and heating degree days - Cities and FUAs — Cooling degree 445.78 Degree days 2025 up 159.8% 247th Precipitation - Cities and FUAs — Change in extreme precipitation 3.68 Days per year 2024 down 54.5% 263rd Precipitation - Cities and FUAs — Extreme precipitation days 24.67 Days per year 2024 down 15.1% 121st Exposure to extreme precipitation — Annual precipitation change 76.63 Millimetres per year 2023 up 124.1% 230th Exposure to extreme temperature — Annual temperature change 1.28 Degrees celsius 2023 up 240.4% 380th Dependency ratio - Cities and FUAs 23.5 Percentage of population aged 15-64 years 2023 up 39.1% 902nd Wind threats - Cities and FUAs — Exposure to wind threats 0 Percentage of area 2023 down 100.0% 271st Coastal flooding - Cities and FUAs — Built-up area exposure to 0.2222 Percentage of built-up area 2022 down 49.4% 153rd R&D personnel by sector of performance and region — R&D Personnel 3,473 Persons 2024 up 39.3% 163rd Internet speed - Cities and FUAs — Uploading speed -17.5 Percentage of national value 2025 down 18.2% 1004th Internet speed - Cities and FUAs — Downloading speed -16.2 Percentage of national value 2025 up 6.9% 1211th