Cooling and heating degree days - Cities and FUAs in Bologna
Bologna: Cooling and heating degree days - Cities and FUAs was 1,234 Degree days in 2025. βΌ Falling
Cooling and heating degree days - Cities and FUAs in Bologna, 1950β2025
Source: Organisation for Economic Co-operation and Development. Measured in Degree days.
Analysis
In 2025, cooling and heating degree days - cities and fuas in Bologna stood at 1,234 Degree days.
That represents a change of down 9.4% on the previous year and down 12.6% over ten years.
Over the whole period, cooling and heating degree days - cities and fuas in Bologna peaked at 2,130 Degree days in 1956 and was at its lowest, 1,134 Degree days, in 2014.
That places Bologna 808th out of 1323 regions with data for 2025, putting it in the middle of the range.
The long-run direction has been consistently falling across the 76 years of available data.
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1950s | 1,756 Degree days | 1,556 Degree days | 2,130 Degree days | 10 |
| 1960s | 1,798 Degree days | 1,557 Degree days | 2,049 Degree days | 10 |
| 1970s | 1,718 Degree days | 1,566 Degree days | 1,845 Degree days | 10 |
| 1980s | 1,743 Degree days | 1,561 Degree days | 1,993 Degree days | 10 |
| 1990s | 1,593 Degree days | 1,381 Degree days | 1,892 Degree days | 10 |
| 2000s | 1,533 Degree days | 1,369 Degree days | 1,789 Degree days | 10 |
| 2010s | 1,475 Degree days | 1,134 Degree days | 1,778 Degree days | 10 |
| 2020s | 1,349 Degree days | 1,234 Degree days | 1,500 Degree days | 6 |
More reference data data for Bologna
- Cooling and heating degree days - Cities and FUAs β Change in heating -382.02 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs β Change in cooling 14.5 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs β Cooling degree 319.26 Degree days (2025)
- Precipitation - Cities and FUAs β Change in extreme precipitation 6.88 Days per year (2024)
- Precipitation - Cities and FUAs β Extreme precipitation days 13.88 Days per year (2024)
- Assumptions for probability of dying by age, sex, type of projection 0.0002 (2100)
- Cooling and heating degree days by NUTS 2 regions - monthly data 352.83 (2025)
- Cooling and heating degree days by NUTS 2 regions - annual data 1,845 (2025)
- Dependency ratio - Cities and FUAs 37.9 Percentage of population aged 15-64 years (2024)
- Wind threats - Cities and FUAs β Exposure to wind threats 0 Percentage of area (2023)
Frequently asked questions
- What is cooling and heating degree days - cities and fuas in Bologna?
- Cooling and heating degree days - cities and fuas in Bologna was 1,234 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 Bologna?
- The highest recorded value was 2,130 Degree days in 1956.
- What is the lowest cooling and heating degree days - cities and fuas recorded in Bologna?
- The lowest recorded value was 1,134 Degree days in 2014.
- How does Bologna rank for cooling and heating degree days - cities and fuas?
- Bologna ranks 808th out of 1323 regions with data for 2025.
- Is cooling and heating degree days - cities and fuas rising or falling in Bologna?
- Over the last ten years it is down 12.6%. The long-run trend across the full record is falling.
- Where does this Bologna 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>