Cooling and heating degree days - Cities and FUAs — Cooling degree in Boulogne-sur-Mer
Boulogne-sur-Mer: Cooling and heating degree days - Cities and FUAs — Cooling degree was 4.78 Degree days in 2025. ◆ Volatile
Cooling and heating degree days - Cities and FUAs — Cooling degree in Boulogne-sur-Mer, 1950–2025
Source: Organisation for Economic Co-operation and Development. Measured in Degree days.
Analysis
Boulogne-sur-Mer recorded 4.78 Degree days for cooling and heating degree days - cities and fuas — cooling degree in 2025.
That represents a change of down 71.7% on the previous year and down 75.7% over ten years.
Over the whole period, cooling and heating degree days - cities and fuas — cooling degree in Boulogne-sur-Mer peaked at 52.5 Degree days in 2022 and was at its lowest, 0.9282 Degree days, in 1972.
That places Boulogne-sur-Mer 1141st out of 1314 regions with data for 2025, putting it in the bottom quarter.
The series is highly variable year to year, so single readings are best treated with caution.
Cooling and heating degree days - Cities and FUAs — Cooling degree in Boulogne-sur-Mer, year by year
| Year | Degree days | Change |
|---|---|---|
| 1950 | 9.75 Degree days | — |
| 1951 | 3.55 Degree days | -63.6% |
| 1952 | 8.45 Degree days | +138.2% |
| 1953 | 8.05 Degree days | -4.8% |
| 1954 | 1.21 Degree days | -85.0% |
| 1955 | 10.13 Degree days | +739.6% |
| 1956 | 2.79 Degree days | -72.5% |
| 1957 | 19.71 Degree days | +606.6% |
| 1958 | 6.62 Degree days | -66.4% |
| 1959 | 27.42 Degree days | +313.9% |
| 1960 | 2.5 Degree days | -90.9% |
| 1961 | 14.27 Degree days | +470.8% |
| 1962 | 2.59 Degree days | -81.8% |
| 1963 | 4.19 Degree days | +61.4% |
| 1964 | 10.95 Degree days | +161.6% |
| 1965 | 1.18 Degree days | -89.2% |
| 1966 | 3.62 Degree days | +207.6% |
| 1967 | 5.92 Degree days | +63.2% |
| 1968 | 5.67 Degree days | -4.2% |
| 1969 | 11.32 Degree days | +99.7% |
| 1970 | 9.85 Degree days | -12.9% |
| 1971 | 5.77 Degree days | -41.5% |
| 1972 | 0.9282 Degree days | -83.9% |
| 1973 | 15.63 Degree days | +1584.3% |
| 1974 | 0.9521 Degree days | -93.9% |
| 1975 | 21.03 Degree days | +2108.3% |
| 1976 | 48.92 Degree days | +132.7% |
| 1977 | 3.06 Degree days | -93.7% |
| 1978 | 2.2 Degree days | -28.0% |
| 1979 | 1.3 Degree days | -41.0% |
| 1980 | 5.5 Degree days | +322.5% |
| 1981 | 5.8 Degree days | +5.6% |
| 1982 | 15.65 Degree days | +169.8% |
| 1983 | 19.32 Degree days | +23.4% |
| 1984 | 11.27 Degree days | -41.7% |
| 1985 | 7.32 Degree days | -35.1% |
| 1986 | 9.53 Degree days | +30.2% |
| 1987 | 7.46 Degree days | -21.7% |
| 1988 | 3.42 Degree days | -54.2% |
| 1989 | 24.08 Degree days | +604.3% |
| 1990 | 31.77 Degree days | +31.9% |
| 1991 | 11.5 Degree days | -63.8% |
| 1992 | 12.83 Degree days | +11.6% |
| 1993 | 5.76 Degree days | -55.1% |
| 1994 | 23.18 Degree days | +302.6% |
| 1995 | 47.55 Degree days | +105.1% |
| 1996 | 11.69 Degree days | -75.4% |
| 1997 | 19.51 Degree days | +66.9% |
| 1998 | 9.07 Degree days | -53.5% |
| 1999 | 20.43 Degree days | +125.2% |
| 2000 | 7.16 Degree days | -65.0% |
| 2001 | 19.22 Degree days | +168.5% |
| 2002 | 10.6 Degree days | -44.8% |
| 2003 | 48.36 Degree days | +356.1% |
| 2004 | 14.66 Degree days | -69.7% |
| 2005 | 19.12 Degree days | +30.4% |
| 2006 | 38 Degree days | +98.8% |
| 2007 | 4.15 Degree days | -89.1% |
| 2008 | 10.02 Degree days | +141.4% |
| 2009 | 13.14 Degree days | +31.2% |
| 2010 | 9.34 Degree days | -28.9% |
| 2011 | 11.13 Degree days | +19.2% |
| 2012 | 10.19 Degree days | -8.5% |
| 2013 | 19.68 Degree days | +93.1% |
| 2014 | 11.94 Degree days | -39.3% |
| 2015 | 19.69 Degree days | +64.9% |
| 2016 | 24.85 Degree days | +26.2% |
| 2017 | 24.8 Degree days | -0.2% |
| 2018 | 34.69 Degree days | +39.9% |
| 2019 | 30.86 Degree days | -11.0% |
| 2020 | 49.53 Degree days | +60.5% |
| 2021 | 11.43 Degree days | -76.9% |
| 2022 | 52.5 Degree days | +359.3% |
| 2023 | 29.51 Degree days | -43.8% |
| 2024 | 16.88 Degree days | -42.8% |
| 2025 | 4.78 Degree days | -71.7% |
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1950s | 9.77 Degree days | 1.21 Degree days | 27.42 Degree days | 10 |
| 1960s | 6.22 Degree days | 1.18 Degree days | 14.27 Degree days | 10 |
| 1970s | 10.97 Degree days | 0.9282 Degree days | 48.92 Degree days | 10 |
| 1980s | 10.94 Degree days | 3.42 Degree days | 24.08 Degree days | 10 |
| 1990s | 19.33 Degree days | 5.76 Degree days | 47.55 Degree days | 10 |
| 2000s | 18.44 Degree days | 4.15 Degree days | 48.36 Degree days | 10 |
| 2010s | 19.72 Degree days | 9.34 Degree days | 34.69 Degree days | 10 |
| 2020s | 27.44 Degree days | 4.78 Degree days | 52.5 Degree days | 6 |
More reference data data for Boulogne-sur-Mer
- Cooling and heating degree days - Cities and FUAs — Change in cooling -11.59 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs 1,510 Degree days (2025)
- Cooling and heating degree days - Cities and FUAs — Change in heating -365.41 Degree days (2025)
- Precipitation - Cities and FUAs — Extreme precipitation days 5 Days per year (2024)
- Precipitation - Cities and FUAs — Change in extreme precipitation 2.68 Days per year (2024)
- Dependency ratio - Cities and FUAs 33.4 Percentage of population aged 15-64 years (2022)
- Wind threats - Cities and FUAs — Exposure to wind threats 100 Percentage of area (2023)
- Coastal flooding - Cities and FUAs — Built-up area exposure to 0.9549 Percentage of built-up area (2022)
- Main mode of transport to work - Cities and FUAs — Employed persons 25,771 Persons (2022)
- Internet speed - Cities and FUAs — Downloading speed 17.2 Percentage of national value (2025)
Frequently asked questions
- What is cooling and heating degree days - cities and fuas — cooling degree in Boulogne-sur-Mer?
- Cooling and heating degree days - cities and fuas — cooling degree in Boulogne-sur-Mer was 4.78 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 — cooling degree recorded in Boulogne-sur-Mer?
- The highest recorded value was 52.5 Degree days in 2022.
- What is the lowest cooling and heating degree days - cities and fuas — cooling degree recorded in Boulogne-sur-Mer?
- The lowest recorded value was 0.9282 Degree days in 1972.
- How does Boulogne-sur-Mer rank for cooling and heating degree days - cities and fuas — cooling degree?
- Boulogne-sur-Mer ranks 1141st out of 1314 regions with data for 2025.
- Is cooling and heating degree days - cities and fuas — cooling degree rising or falling in Boulogne-sur-Mer?
- Over the last ten years it is down 75.7%. The long-run trend across the full record is volatile.
- Where does this Boulogne-sur-Mer 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 — Cooling degree days. Statizoid updates them automatically from the source API.
Download this data
CSV · JSON — 76 observations, free to reuse under OECD Terms and Conditions (attribution required).
About this data
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. Data sources and methodology The indicators use 0.1-degree resolution grids from the ERA5-Land dataset. 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 22°C for CDDs and 15°C for HDDs. 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. Defining FUAs and cities The OECD, in cooperation with the EU, has developed a harmonised definition of functional urban areas (FUAs) to capture the economic and functional reach of cities based on daily commuting patterns (OECD, 2012). FUAs consist of: A city – defined by urban centres in the degree of urbanisation, adapted to the closest local administrative units to define a city. A commuting zone – including all local areas where at least 15% of employed residents work in the city. The delineation process includes: Assigning municipalities surrounded by a single FUA to that FUA. Excluding non-contiguous municipalities. The correspondence table between SAUs and FUAs/cities is available in parquet and csv format. The definition identifies 1 272 FUAs and 1 269 cities in all OECD member countries except Costa Rica and three accession countries. Cite this dataset OECD Regions, cities and local areas database (Cooling and heating degree days - Cities and FUAs), http://oe.cd/geostats Further information OECD Local Data Portal OECD Regions and Cities at a Glance For questions and/or comments, please email CitiesStat@oecd.org