Heat stress - Cities and FUAs — Mean population exposure to heat in Summit
Summit: Heat stress - Cities and FUAs — Mean population exposure to heat was 58.95 Days per year in 2025. ▲ Rising
Heat stress - Cities and FUAs — Mean population exposure to heat in Summit, 1981–2025
Source: Organisation for Economic Co-operation and Development. Measured in Days per year.
Analysis
The most recent figure for heat stress - cities and fuas — mean population exposure to heat in Summit is 58.95 Days per year, measured in 2025.
That represents a change of up 16.0% on the previous year and up 68.2% over ten years.
Over the whole period, heat stress - cities and fuas — mean population exposure to heat in Summit peaked at 72.01 Days per year in 1991 and was at its lowest, 13.25 Days per year, in 2009.
Summit ranks 491st of 1315 regions on this measure, in the middle of the range.
The long-run direction has been consistently rising across the 45 years of available data.
Heat stress - Cities and FUAs — Mean population exposure to heat in Summit, year by year
| Year | Days per year | Change |
|---|---|---|
| 1981 | 22.04 Days per year | — |
| 1982 | 35.83 Days per year | +62.6% |
| 1983 | 60.14 Days per year | +67.8% |
| 1984 | 29.86 Days per year | -50.3% |
| 1985 | 23.48 Days per year | -21.4% |
| 1986 | 29.43 Days per year | +25.4% |
| 1987 | 51.82 Days per year | +76.1% |
| 1988 | 52.56 Days per year | +1.4% |
| 1989 | 36.39 Days per year | -30.8% |
| 1990 | 28.66 Days per year | -21.2% |
| 1991 | 72.01 Days per year | +151.2% |
| 1992 | 15.58 Days per year | -78.4% |
| 1993 | 43.17 Days per year | +177.0% |
| 1994 | 30.69 Days per year | -28.9% |
| 1995 | 50.12 Days per year | +63.3% |
| 1996 | 35.51 Days per year | -29.1% |
| 1997 | 24.89 Days per year | -29.9% |
| 1998 | 48.82 Days per year | +96.2% |
| 1999 | 49.13 Days per year | +0.6% |
| 2000 | 14.89 Days per year | -69.7% |
| 2001 | 34.98 Days per year | +134.9% |
| 2002 | 58.94 Days per year | +68.5% |
| 2003 | 27.09 Days per year | -54.0% |
| 2004 | 21.31 Days per year | -21.4% |
| 2005 | 61.72 Days per year | +189.6% |
| 2006 | 35.33 Days per year | -42.8% |
| 2007 | 56.42 Days per year | +59.7% |
| 2008 | 38.61 Days per year | -31.6% |
| 2009 | 13.25 Days per year | -65.7% |
| 2010 | 52.76 Days per year | +298.3% |
| 2011 | 56.4 Days per year | +6.9% |
| 2012 | 64.66 Days per year | +14.6% |
| 2013 | 32.43 Days per year | -49.8% |
| 2014 | 25.98 Days per year | -19.9% |
| 2015 | 35.04 Days per year | +34.9% |
| 2016 | 65.36 Days per year | +86.5% |
| 2017 | 36.39 Days per year | -44.3% |
| 2018 | 55.31 Days per year | +52.0% |
| 2019 | 43.75 Days per year | -20.9% |
| 2020 | 50.39 Days per year | +15.2% |
| 2021 | 49.04 Days per year | -2.7% |
| 2022 | 40.07 Days per year | -18.3% |
| 2023 | 32.9 Days per year | -17.9% |
| 2024 | 50.84 Days per year | +54.5% |
| 2025 | 58.95 Days per year | +16.0% |
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1980s | 37.95 Days per year | 22.04 Days per year | 60.14 Days per year | 9 |
| 1990s | 39.86 Days per year | 15.58 Days per year | 72.01 Days per year | 10 |
| 2000s | 36.25 Days per year | 13.25 Days per year | 61.72 Days per year | 10 |
| 2010s | 46.81 Days per year | 25.98 Days per year | 65.36 Days per year | 10 |
| 2020s | 47.03 Days per year | 32.9 Days per year | 58.95 Days per year | 6 |
More population data for Summit
- Population by age and sex - Cities and FUAs 538,370 Persons (2024)
- Foreign-born population - Cities and FUAs 5.7 Percentage of population (2023)
- Population and built-up density - Cities and FUAs — Urbanised area 94 Square kilometres (2030)
Frequently asked questions
- What is heat stress - cities and fuas — mean population exposure to heat in Summit?
- Heat stress - cities and fuas — mean population exposure to heat in Summit was 58.95 Days per year in 2025, according to Organisation for Economic Co-operation and Development.
- What is the highest heat stress - cities and fuas — mean population exposure to heat recorded in Summit?
- The highest recorded value was 72.01 Days per year in 1991.
- What is the lowest heat stress - cities and fuas — mean population exposure to heat recorded in Summit?
- The lowest recorded value was 13.25 Days per year in 2009.
- How does Summit rank for heat stress - cities and fuas — mean population exposure to heat?
- Summit ranks 491st out of 1315 regions with data for 2025.
- Is heat stress - cities and fuas — mean population exposure to heat rising or falling in Summit?
- Over the last ten years it is up 68.2%. The long-run trend across the full record is rising.
- Where does this Summit data come from?
- The figures come from Organisation for Economic Co-operation and Development, published as part of Heat stress - Cities and FUAs — Mean population exposure to heat stress. Statizoid updates them automatically from the source API.
Download this data
CSV · JSON — 45 observations, free to reuse under OECD Terms and Conditions (attribution required).
About this data
This dataset provides an indicator of population exposure to heat stress. Data sources and methodology The indicator uses the Universal Thermal Comfort Index (UTCI). The UTCI enables to assess the impact of atmospheric conditions on the human body by considering air temperature, wind, radiation and humidity. UTCI values from 32°C to 38°C are considered as strong heat stress, from 38°C to 46°C as very strong heat stress, and above 46°C as extreme heat stress. Population exposure to heat stress was computed using the hourly thermal comfort indices grids from the Copernicus Climate Data Store (Di Napoli C. et al.). For each 0.25° by 0.25° grid cell, the number of days for which the maximum UTCI value is above each heat stress threshold (32°C, 38°C and 46°C) is computed. FUA and city level indicators correspond to the population-weighted average number of days above each heat stress threshold, obtained by intersecting the computed grid with the Global Human Settlement Population layer (European Commission, GHSL Data Package 2023). 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 (Heat stress - 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