Air temperature, hot days, tropical nights and icing days - Cities in Hartford
Hartford: Air temperature, hot days, tropical nights and icing days - Cities was 2.29 Degrees celsius in 2025. ◆ Volatile
Air temperature, hot days, tropical nights and icing days - Cities in Hartford, 1981–2025
Source: Organisation for Economic Co-operation and Development. Measured in Degrees celsius.
Analysis
The most recent figure for air temperature, hot days, tropical nights and icing days - cities in Hartford is 2.29 Degrees celsius, measured in 2025. That is the highest value across all 45 years on record.
That represents a change of up 65.5% on the previous year and up 1,773.6% over ten years.
Over the whole period, air temperature, hot days, tropical nights and icing days - cities in Hartford peaked at 2.29 Degrees celsius in 2025 and was at its lowest, -0.9909 Degrees celsius, in 2003.
That places Hartford 348th out of 1314 regions with data for 2025, putting it in the middle of the range.
The series is highly variable year to year, so single readings are best treated with caution.
Air temperature, hot days, tropical nights and icing days - Cities in Hartford, year by year
| Year | Degrees celsius | Change |
|---|---|---|
| 1981 | -0.4082 Degrees celsius | — |
| 1982 | -0.5474 Degrees celsius | +34.1% |
| 1983 | 0.2273 Degrees celsius | -141.5% |
| 1984 | -0.0382 Degrees celsius | -116.8% |
| 1985 | -0.2666 Degrees celsius | +597.9% |
| 1986 | -0.36 Degrees celsius | +35.1% |
| 1987 | -0.379 Degrees celsius | +5.3% |
| 1988 | -0.3335 Degrees celsius | -12.0% |
| 1989 | -0.6875 Degrees celsius | +106.2% |
| 1990 | 0.9221 Degrees celsius | -234.1% |
| 1991 | 1.2 Degrees celsius | +29.9% |
| 1992 | -0.7764 Degrees celsius | -164.8% |
| 1993 | -0.2223 Degrees celsius | -71.4% |
| 1994 | -0.3773 Degrees celsius | +69.8% |
| 1995 | 0.0078 Degrees celsius | -102.1% |
| 1996 | -0.7293 Degrees celsius | -9484.2% |
| 1997 | -0.5039 Degrees celsius | -30.9% |
| 1998 | 1.09 Degrees celsius | -317.3% |
| 1999 | 0.761 Degrees celsius | -30.5% |
| 2000 | -0.734 Degrees celsius | -196.4% |
| 2001 | 0.4634 Degrees celsius | -163.1% |
| 2002 | 0.7033 Degrees celsius | +51.8% |
| 2003 | -0.9909 Degrees celsius | -240.9% |
| 2004 | -0.4564 Degrees celsius | -53.9% |
| 2005 | 0.1009 Degrees celsius | -122.1% |
| 2006 | 0.9297 Degrees celsius | +821.6% |
| 2007 | 0.3698 Degrees celsius | -60.2% |
| 2008 | 0.3352 Degrees celsius | -9.4% |
| 2009 | -0.4523 Degrees celsius | -235.0% |
| 2010 | 1.15 Degrees celsius | -354.4% |
| 2011 | 0.5945 Degrees celsius | -48.3% |
| 2012 | 1.68 Degrees celsius | +183.0% |
| 2013 | -0.0316 Degrees celsius | -101.9% |
| 2014 | -0.5083 Degrees celsius | +1508.3% |
| 2015 | 0.1225 Degrees celsius | -124.1% |
| 2016 | 1.2 Degrees celsius | +876.6% |
| 2017 | 0.5337 Degrees celsius | -55.4% |
| 2018 | 0.5509 Degrees celsius | +3.2% |
| 2019 | 0.2517 Degrees celsius | -54.3% |
| 2020 | 1.37 Degrees celsius | +445.3% |
| 2021 | 0.9335 Degrees celsius | -32.0% |
| 2022 | 0.8745 Degrees celsius | -6.3% |
| 2023 | 1.35 Degrees celsius | +54.9% |
| 2024 | 1.39 Degrees celsius | +2.4% |
| 2025 | 2.29 Degrees celsius | +65.5% |
Averages by decade
| Decade | Average | Lowest | Highest | Years |
|---|---|---|---|---|
| 1980s | -0.3104 Degrees celsius | -0.6875 Degrees celsius | 0.2273 Degrees celsius | 9 |
| 1990s | 0.1374 Degrees celsius | -0.7764 Degrees celsius | 1.2 Degrees celsius | 10 |
| 2000s | 0.0268 Degrees celsius | -0.9909 Degrees celsius | 0.9297 Degrees celsius | 10 |
| 2010s | 0.5543 Degrees celsius | -0.5083 Degrees celsius | 1.68 Degrees celsius | 10 |
| 2020s | 1.37 Degrees celsius | 0.8745 Degrees celsius | 2.29 Degrees celsius | 6 |
More climate change data for Hartford
- Air temperature, hot days, tropical nights and icing days - Cities 12.07 Degrees celsius (2025)
- Climate projections by scenario, 2030–2060 – Cities and FUAs 12.78 Degrees celsius (2060)
- Climate projections by scenario, 2030–2060 – Cities and FUAs 2.2 Degrees celsius (2060)
- Greenhouse gas emissions - Cities and FUAs — GHG emissions from 0.01 Tonnes of CO2-equivalent (2024)
- Greenhouse gas emissions - Cities and FUAs — GHG emissions from 1.7 Tonnes of CO2-equivalent (2024)
- Greenhouse gas emissions - Cities and FUAs — GHG emissions from 1.29 Tonnes of CO2-equivalent (2024)
- Greenhouse gas emissions - Cities and FUAs — GHG emissions from 1.24 Tonnes of CO2-equivalent (2024)
- Greenhouse gas emissions - Cities and FUAs — GHG emissions from power 2.09 Tonnes of CO2-equivalent (2024)
- Greenhouse gas emissions - Cities and FUAs — GHG emissions from road 2.32 Tonnes of CO2-equivalent (2024)
- Greenhouse gas emissions - Cities and FUAs — GHG emissions total 7.74 Tonnes of CO2-equivalent (2024)
Frequently asked questions
- What is air temperature, hot days, tropical nights and icing days - cities in Hartford?
- Air temperature, hot days, tropical nights and icing days - cities in Hartford was 2.29 Degrees celsius in 2025, according to Organisation for Economic Co-operation and Development.
- What is the highest air temperature, hot days, tropical nights and icing days - cities recorded in Hartford?
- The highest recorded value was 2.29 Degrees celsius in 2025.
- What is the lowest air temperature, hot days, tropical nights and icing days - cities recorded in Hartford?
- The lowest recorded value was -0.9909 Degrees celsius in 2003.
- How does Hartford rank for air temperature, hot days, tropical nights and icing days - cities?
- Hartford ranks 348th out of 1314 regions with data for 2025.
- Is air temperature, hot days, tropical nights and icing days - cities rising or falling in Hartford?
- Over the last ten years it is up 1,773.6%. The long-run trend across the full record is volatile.
- Where does this Hartford data come from?
- The figures come from Organisation for Economic Co-operation and Development, published as part of Air temperature, hot days, tropical nights and icing days - Cities and FUAs — Change in air temperature at 2 meters from 1981–2010 period. 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 indicators of air temperature, hot days, tropical nights and icing days. Data sources and methodology Indicators are estimated using ERA5-Land data. Air temperature indicators correspond to the average annual air temperature at a height of 2 meters. Hot days correspond to the number of days when the maximum temperature exceeds 35°C. Tropical nights correspond to the days when the minimum temperature is above 20°C, and icing days to the number of days when the maximum temperature is below 0°C. 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. 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 (Air temperature, hot days, tropical nights and icing days - 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