Air temperature, hot days, tropical nights and icing days - Regions

<p style="text-align: justify;">This dataset provides indicators on air temperature, hot days, tropical nights, and icing days, in large (TL2) and small (TL3) regions.</p> <p><strong>Data definition and source</strong></p> <p style="text-align: justify;">Air temperature indicators correspond to the annual average air temperature at a height of 2 meters. Hot days refer to the number of days when the maximum temperature exceeds 35&deg;C. Tropical nights refer to days when the minimum temperature is above 20&deg;C, and icing days refer to the number of days when the maximum temperature is below 0&deg;C. The data is based on <a href="https://developers.google.com/earth-engine/datasets/catalog/ECMWF_ERA5_LAND_DAILY_AGGR">ERA5-Land reanalysis</a> dataset.</p> <p style="text-align: justify;">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.</p> <p style="text-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> <p><strong>Definition of regions</strong></p> <p style="text-align: justify;">Regions are subnational units below national boundaries. OECD countries have two regional levels: large regions (territorial level 2 or TL2) and small regions (territorial level 3 or TL3). For more information, see the OECD Territorial Grid <a href="https://webfs-cfe.oecd.org/files/.Stat/region/OECD_territorial-grid_TL2024.pdf">(pdf)</a> and the OECD Territorial Correspondence Table <a href="https://webfs-cfe.oecd.org/files/.Stat/region/OECD%20Territorial%20correspondence%20-%20TL2024c.xlsx">(xlsx)</a>.</p> <p><strong>Cite this dataset</strong></p> <p>OECD Regions, Cities and Local Areas database&nbsp;<a href="http://oe.cd/geostats">http://oe.cd/geostats</a>.</p> <p><strong>Further information</strong></p> <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>For questions and/or comments, please email <a href="mailto:RegionStat@oecd.org">RegionStat@oecd.org</a>.</p>

Cite as: OECD, Air temperature, hot days, tropical nights and icing days - Regions (OECD.CFE.EDS:DSD_REG_CLIM@DF_AIR_TEMP).