Cooling and heating degree days - Cities and FUAs in Siirt

Siirt: Cooling and heating degree days - Cities and FUAs was 1,400 Degree days in 2025. β–Ό Falling

Latest (2025)
1,400 Degree days
Change on year
down 14.8%
Rank
728th
of 1323 regions
All-time high
2,640 Degree days
in 1992
All-time low
1,340 Degree days
in 2018
Years of data
76
1950–2025

Cooling and heating degree days - Cities and FUAs in Siirt, 1950–2025

01.0k2.0k3.0k195019872025

Source: Organisation for Economic Co-operation and Development. Measured in Degree days.

Analysis

Siirt recorded 1,400 Degree days for cooling and heating degree days - cities and fuas in 2025.

The figure is down 14.8% on the previous year and down 19.3% over ten years.

Over the whole period, cooling and heating degree days - cities and fuas in Siirt peaked at 2,640 Degree days in 1992 and was at its lowest, 1,340 Degree days, in 2018.

Siirt ranks 728th of 1323 regions on this measure, in the middle of the range.

The long-run direction has been consistently falling across the 76 years of available data.

Averages by decade

DecadeAverage LowestHighest Years
1950s 2,020 Degree days 1,623 Degree days 2,273 Degree days 10
1960s 1,925 Degree days 1,505 Degree days 2,309 Degree days 10
1970s 2,040 Degree days 1,709 Degree days 2,358 Degree days 10
1980s 2,077 Degree days 1,907 Degree days 2,378 Degree days 10
1990s 2,030 Degree days 1,695 Degree days 2,640 Degree days 10
2000s 1,851 Degree days 1,689 Degree days 1,945 Degree days 10
2010s 1,687 Degree days 1,340 Degree days 1,955 Degree days 10
2020s 1,572 Degree days 1,400 Degree days 1,658 Degree days 6

More reference data data for Siirt

All data for Siirt β†’

Frequently asked questions

What is cooling and heating degree days - cities and fuas in Siirt?
Cooling and heating degree days - cities and fuas in Siirt was 1,400 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 Siirt?
The highest recorded value was 2,640 Degree days in 1992.
What is the lowest cooling and heating degree days - cities and fuas recorded in Siirt?
The lowest recorded value was 1,340 Degree days in 2018.
How does Siirt rank for cooling and heating degree days - cities and fuas?
Siirt ranks 728th out of 1323 regions with data for 2025.
Is cooling and heating degree days - cities and fuas rising or falling in Siirt?
Over the last ten years it is down 19.3%. The long-run trend across the full record is falling.
Where does this Siirt 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.

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Cooling and heating degree days - Cities and FUAs in Siirt. Statizoid, drawing on Organisation for Economic Co-operation and Development. Retrieved 17 August 2026, from https://reference.statizoid.com/stat/cooling-and-heating-degree-days-cities-and-fuas/siirt/

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About this data

Indicator
Cooling and heating degree days - Cities and FUAs
Unit
Degree days
Source
Organisation for Economic Co-operation and Development
Licence
OECD Terms and Conditions (attribution required)
Coverage
1,325 places, 100,700 data points, 1950–2025
Last refreshed

<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> – 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> – 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>