Seattle in 2050: climate change in numbers
Seattle has warmed 1.1 °C, comparing the last ten years (2016–2025) with 1951–1980 — about as fast as the world as a whole (+1.1 °C). By 2050, it is heading for a climate that no large city has today.
2050 = 2040–2059 average, intermediate emissions (SSP2-4.5), median of CMIP6 climate models. “Today” = 1991–2020. Model range for average temperature: 12.2–13.9 °C.
Seattle: average annual temperature, 1950–2025 (°C)
1950 → 2025. Seattle's warming stripes: each stripe is one year's average temperature.
What Seattle's climate will feel like
We compared Seattle's projected 2050 climate with today's climate in more than 1,000 large cities. None is a close match; the nearest is Johannesburg, South Africa. Scientists call this a novel climate: conditions the city's people, buildings and infrastructure have no local experience of.
| Seattle today | Seattle 2050 | Johannesburg today | |
|---|---|---|---|
| Average temperature | 11.4 °C | 12.9 °C | 16.1 °C |
| Average daily high | 15.7 °C | 17.1 °C | 22.9 °C |
| Hottest day | 32 °C | 34 °C | 32 °C |
| Frost days | 13 | 5 | 8 |
| Rainfall | 1,383 mm | 1,428 mm | 791 mm |
A year in Seattle, 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 Seattle
Tropical nights in Seattle (never cooler than 20 °C)
Frost days in Seattle (below 0 °C)
What changes by 2050
- The average temperature rises a further 1.5 °C compared with 1991–2020 (model range 0.8–2.5 °C).
- Days above 30 °C (86 °F) rise from about 4 a year (1991–2020) to about 16 by 2040–2059.
- Frost days fall from about 13 to 5 a year: shorter, milder winters.
Dangerous heat in Seattle
Even by 2090 under very high emissions, Seattle is not projected to have days with a heat index of 39 °C or more in a typical year. See where dangerous heat spreads worldwide.
Sea level at Seattle
The sea at Seattle is projected to rise about 19 cm by 2050 and 53 cm by 2100 (IPCC AR6, intermediate emissions). See the full sea level projection for Seattle.
Under high emissions
If emissions keep rising (SSP5-8.5), Seattle would average 13.2 °C by 2040–2059, with a hottest day around 34 °C and 21 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 Seattle with…Climate change in the United StatesVancouverSan FranciscoLas VegasLos Angeles
Frequently asked questions
How hot will Seattle be in 2050?
Under an intermediate emissions scenario (SSP2-4.5), Seattle's average annual temperature in 2040–2059 is projected at about 12.9 °C (range 12.2–13.9 °C across climate models), compared with 11.4 °C in 1991–2020. The hottest day of a typical year reaches about 34 °C (93 °F).
Is Seattle getting hotter?
Yes. The last ten years (2016–2025) averaged 1.1 °C warmer than 1951–1980 in Seattle, about as fast as the global average of 1.1 °C over the same period (Copernicus ERA5).
Which city will Seattle feel like in 2050?
No large city today has a climate quite like Seattle's projected 2050 climate. The closest match is Johannesburg, South Africa, but the fit is loose — Seattle is heading into a climate with no close equivalent among the world's large cities.
What would happen under high emissions?
Under a very high emissions scenario (SSP5-8.5), Seattle's average temperature in 2040–2059 is projected at 13.2 °C and the hottest day at about 34 °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