Reference Data in Alphen aan den Rijn 11 indicators covering reference data for Alphen aan den Rijn. IndicatorLatest Year10-yr change Rank Cooling and heating degree days - Cities and FUAs — Cooling degree 12.14 Degree days 2025 down 57.7% 1059th Cooling and heating degree days - Cities and FUAs — Change in cooling -11.44 Degree days 2025 down 323.8% 726th Cooling and heating degree days - Cities and FUAs 1,972 Degree days 2025 up 10.4% 407th Cooling and heating degree days - Cities and FUAs — Change in heating -57.79 Degree days 2025 up 76.3% 199th Precipitation - Cities and FUAs — Extreme precipitation days 2.2 Days per year 2024 up 37.4% 1098th Precipitation - Cities and FUAs — Change in extreme precipitation 0.3665 Days per year 2024 up 257.5% 783rd Dependency ratio - Cities and FUAs 32.5 Percentage of population aged 15-64 years 2025 up 24.0% 448th Wind threats - Cities and FUAs — Exposure to wind threats 100 Percentage of area 2023 up 49.8% 1st Coastal flooding - Cities and FUAs — Built-up area exposure to 100 Percentage of built-up area 2022 unchanged 1st Internet speed - Cities and FUAs — Downloading speed 7.1 Percentage of national value 2025 down 37.2% 592nd Internet speed - Cities and FUAs — Uploading speed 11.8 Percentage of national value 2025 down 68.4% 450th