Cooling and heating degree days - Cities and FUAs in Siegen
Siegen: Cooling and heating degree days - Cities and FUAs was 2,640 Degree days in 2025. βΌ Falling
Cooling and heating degree days - Cities and FUAs in Siegen, 1950β2025
Source: Organisation for Economic Co-operation and Development. Measured in Degree days.
Analysis
The most recent figure for cooling and heating degree days - cities and fuas in Siegen is 2,640 Degree days, measured in 2025.
The figure is up 13.1% on the previous year and up 4.9% over ten years.
Over the whole period, cooling and heating degree days - cities and fuas in Siegen peaked at 3,359 Degree days in 1956 and was at its lowest, 2,224 Degree days, in 2014.
Siegen ranks 136th of 1323 regions on this measure, in the top quarter.
The long-run direction has been consistently falling across the 76 years of available data.
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1950s | 2,952 Degree days | 2,573 Degree days | 3,359 Degree days | 10 |
| 1960s | 2,985 Degree days | 2,632 Degree days | 3,321 Degree days | 10 |
| 1970s | 2,939 Degree days | 2,719 Degree days | 3,156 Degree days | 10 |
| 1980s | 2,952 Degree days | 2,495 Degree days | 3,270 Degree days | 10 |
| 1990s | 2,763 Degree days | 2,505 Degree days | 3,307 Degree days | 10 |
| 2000s | 2,635 Degree days | 2,412 Degree days | 2,813 Degree days | 10 |
| 2010s | 2,600 Degree days | 2,224 Degree days | 3,196 Degree days | 10 |
| 2020s | 2,432 Degree days | 2,239 Degree days | 2,688 Degree days | 6 |
More reference data data for Siegen
- Cooling and heating degree days - Cities and FUAs β Cooling degree 19.81 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs β Change in cooling -5.15 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs β Change in heating -146.66 Degree days (2025)
- Precipitation - Cities and FUAs β Extreme precipitation days 8.5 Days per year (2024)
- Precipitation - Cities and FUAs β Change in extreme precipitation 3.22 Days per year (2024)
- Dependency ratio - Cities and FUAs 32 Percentage of population aged 15-64 years (2025)
- Wind threats - Cities and FUAs β Exposure to wind threats 0 Percentage of area (2023)
- Coastal flooding - Cities and FUAs β Built-up area exposure to 0 Percentage of built-up area (2022)
- Internet speed - Cities and FUAs β Downloading speed -4.3 Percentage of national value (2025)
- Internet speed - Cities and FUAs β Uploading speed -39.9 Percentage of national value (2025)
Frequently asked questions
- What is cooling and heating degree days - cities and fuas in Siegen?
- Cooling and heating degree days - cities and fuas in Siegen was 2,640 Degree days in 2025, according to Organisation for Economic Co-operation and Development.
- What is the highest cooling and heating degree days - cities and fuas recorded in Siegen?
- The highest recorded value was 3,359 Degree days in 1956.
- What is the lowest cooling and heating degree days - cities and fuas recorded in Siegen?
- The lowest recorded value was 2,224 Degree days in 2014.
- How does Siegen rank for cooling and heating degree days - cities and fuas?
- Siegen ranks 136th out of 1323 regions with data for 2025.
- Is cooling and heating degree days - cities and fuas rising or falling in Siegen?
- Over the last ten years it is up 4.9%. The long-run trend across the full record is falling.
- Where does this Siegen data come from?
- The figures come from Organisation for Economic Co-operation and Development, published as part of Cooling and heating degree days - Cities and FUAs. Statizoid updates them automatically from the source API.
Download this data
CSV Β· JSON β 76 observations, free to reuse under OECD Terms and Conditions (attribution required).
About this data
<p align="justify">This dataset provides indicators of Cooling and Heating Degree Days (CDDs and HDDs) for FUAs and cities. CDDs and HDDs are measurements used to estimate energy usage based on outdoor temperature. CDD measures the demand for cooling, while HDD measures the demand for heating, both calculated relative to a baseline temperature.</p> <h3>Data sources and methodology</h3> <p align="justify"> The indicators use 0.1-degree resolution grids from the <a href=https://developers.google.com/earth-engine/datasets/catalog/ECMWF_ERA5_LAND_DAILY_AGGR>ERA5-Land dataset</a>. ERA5-Land is used as it provides harmonised, globally consistent coverage at fine spatial resolution (0.1 degree), enabling the production of comparable subnational indicators also where national meteorological data are not available at the required scale. Annual CDDs are the sum over a year of the differences between the daily mean outdoor air temperature and the threshold temperature when the outdoor temperature is above the threshold temperature. HDDs are the sum over a year of the differences between the threshold temperature and the daily mean outdoor air temperature when the outdoor temperature is below the threshold temperature. Threshold temperatures are set to 22Β°C for CDDs and 15Β°C for HDDs.</p> <p align="justify"> These estimates may differ from official subnational climate statistics due to differences in methodological approaches, such as the use of reanalysis based top down modelling versus in situ observations, along with variations in input data sources, spatial resolution, and the models and algorithms used to generate temperature estimates. </p> <h3>Defining FUAs and cities</h3> <p align="justify">The OECD, in cooperation with the EU, has developed a harmonised <a href="https://www.oecd.org/en/data/datasets/oecd-definition-of-cities-and-functional-urban-areas.html">definition of functional urban areas</a> (FUAs) to capture the economic and functional reach of cities based on daily commuting patterns <a href=https://doi.org/10.1787/9789264174108-en>(OECD, 2012)</a>. FUAs consist of: <ol> <li><b>A city</b> β defined by urban centres in the degree of urbanisation, adapted to the closest local administrative units to define a city.</li> <li><b>A commuting zone</b> β including all local areas where at least 15% of employed residents work in the city.</li> </ol> The delineation process includes: <ul> <li>Assigning municipalities surrounded by a single FUA to that FUA.</li> <li>Excluding non-contiguous municipalities.</li> </ul> <p> The correspondence table between SAUs and FUAs/cities is available in <a href=https://webfs-cfe.oecd.org/files/.Stat/cities_local_areas/fua_cities_sau_mapping.parquet>parquet </a> and <a href=https://webfs-cfe.oecd.org/files/.Stat/cities_local_areas/fua_cities_sau_mapping.csv>csv</a> format. </p> The definition identifies 1 272 FUAs and 1 269 cities in all OECD member countries except Costa Rica and three accession countries.</p> <h3>Cite this dataset</h3> <p>OECD Regions, cities and local areas database (<a href="http://data-explorer.oecd.org/s/1dj">Cooling and heating degree days - Cities and FUAs</a>),Β <a href=http://oe.cd/geostats>http://oe.cd/geostats</a></p> <h3>Further information</h3> <ul> <li> <a href=https://localdataportal.oecd.org/>OECD Local Data Portal </a> </li> <li> <a href=https://www.oecd.org/en/publications/oecd-regions-and-cities-at-a-glance-2024_f42db3bf-en.html/>OECD Regions and Cities at a Glance </a> </li> </ul> <p align="justify">For questions and/or comments, please email <a href="mailto:CitiesStat@oecd.org">CitiesStat@oecd.org</a>