Boston in 2050: climate change in numbers
Boston has warmed 1.6 °C, comparing the last ten years (2016–2025) with 1951–1980 — faster than the world as a whole (+1.1 °C). By 2050, its climate is projected to feel like Seoul, South Korea today.
2050 = 2040–2059 average, intermediate emissions (SSP2-4.5), median of CMIP6 climate models. “Today” = 1991–2020. Model range for average temperature: 11.5–13.0 °C.
Boston: average annual temperature, 1950–2025 (°C)
1950 → 2025. Boston's warming stripes: each stripe is one year's average temperature.
What Boston's climate will feel like
Matching temperature, heat extremes, frost days and rainfall against the current climate of more than 1,000 large cities, Boston's 2050 climate is closest to Seoul, South Korea — about 10,900 km away.
| Boston today | Boston 2050 | Seoul today | |
|---|---|---|---|
| Average temperature | 10.6 °C | 12.5 °C | 12.1 °C |
| Average daily high | 14.5 °C | 16.3 °C | 16.9 °C |
| Hottest day | 33 °C | 35 °C | 34 °C |
| Frost days | 84 | 63 | 110 |
| Rainfall | 1,165 mm | 1,247 mm | 1,228 mm |
A year in Boston, day by day
Each square is one day of the year; the coloured squares are the days that cross the threshold in an average year.
Days above 30 °C (86 °F) in Boston
Tropical nights in Boston (never cooler than 20 °C)
Frost days in Boston (below 0 °C)
What changes by 2050
- The average temperature rises a further 1.9 °C compared with 1991–2020 (model range 1.0–2.4 °C).
- Days above 30 °C (86 °F) rise from about 10 a year (1991–2020) to about 19 by 2040–2059.
- Tropical nights — when it never cools below 20 °C — increase from about 25 to 49 a year, making heatwaves harder on health.
- Frost days fall from about 84 to 63 a year: shorter, milder winters.
- Annual rainfall is projected to increase by about 6%, though precipitation projections are less certain than temperature.
Dangerous heat in Boston
Days a year when the heat index — temperature and humidity combined — reaches 39 °C, the level the US National Weather Service calls Danger: 0 in 1995–2014, 0 by 2050 and 0 by 2090 under intermediate emissions, or 1 by 2090 if emissions keep rising. See where dangerous heat spreads worldwide.
Sea level at Boston
The sea at Boston is projected to rise about 34 cm by 2050 and 78 cm by 2100 (IPCC AR6, intermediate emissions). See the full sea level projection for Boston.
Under high emissions
If emissions keep rising (SSP5-8.5), Boston would average 12.8 °C by 2040–2059, with a hottest day around 35 °C and 26 days above 30 °C (86 °F) a year. By mid-century the scenarios are still close; the choices made now mostly decide what happens after 2050 — see the world in 2050.
More places
Compare Boston with…Climate change in the United StatesNew York CityMontrealWashingtonToronto
Frequently asked questions
How hot will Boston be in 2050?
Under an intermediate emissions scenario (SSP2-4.5), Boston's average annual temperature in 2040–2059 is projected at about 12.5 °C (range 11.5–13.0 °C across climate models), compared with 10.6 °C in 1991–2020. The hottest day of a typical year reaches about 35 °C (95 °F).
Is Boston getting hotter?
Yes. The last ten years (2016–2025) averaged 1.6 °C warmer than 1951–1980 in Boston, faster than the global average of 1.1 °C over the same period (Copernicus ERA5).
Which city will Boston feel like in 2050?
By 2040–2059, Boston's climate is projected to resemble the climate of Seoul, South Korea today, based on temperature, heat extremes, frost and rainfall.
What would happen under high emissions?
Under a very high emissions scenario (SSP5-8.5), Boston's average temperature in 2040–2059 is projected at 12.8 °C and the hottest day at about 35 °C. The differences between scenarios grow much larger after 2050.
Sources: World Bank Climate Change Knowledge Portal (CMIP6 0.25°, ERA5 0.25°); Copernicus ERA5 reanalysis (C3S/ECMWF); NASA NEX-GDDP-CMIP6 (Thrasher et al. 2022); GeoNames
Method: Delta method: ERA5 1995–2014 + CMIP6 ensemble change 2040–2059 vs 1995–2014. Values are for the ~25 km grid cell containing the city and can differ from a single weather station, especially for coastal and mountain cities. Methodology · Download CSV
Licence: Derived from ERA5 (CC BY 4.0, Copernicus/ECMWF), CMIP6 via World Bank CCKP (CC BY-SA 4.0) and GeoNames (CC BY 4.0). City data on this site: CC BY-SA 4.0. · Generated 17 October 2026