Home / United States / Washington
Washington climate
Typical historical weather for Washington, United States, averaged across 10 years of hourly climate data. Pick a date for a specific day.
Data last updated: 31 December 2025
Want today's actual conditions instead? See the current forecast for Washington. Planning a garden? See the gardening & growing season planner. Or browse the 365-day climate calendar.
Annual average
13.5°C
across all months
Warmest month
31°C
Jul average high
Coolest month
-3.4°C
Jan average low
Annual rainfall
1094mm
total per year
Washington is typically hottest in July and coolest in January, a swing of about 34.4°C across the year. About 32% of annual rainfall falls in the three wettest months (May is typically wettest, November driest).
Monthly averages
Average daily high/low temperature (band) and monthly rainfall (bars).
| Month | Avg high | Avg low | Rainfall | Wet days | Humidity | Wind | Cloud | Solar |
|---|---|---|---|---|---|---|---|---|
| Jan | 5.6°C · record 12.8°C–23°C | -3.4°C · record -21.3°C–-3.9°C | 83mm | 9 | 65% | 2.6 m/s | 57% | 2.3 kWh/m² |
| Feb | 9.4°C · record 18°C–26.6°C | -0.5°C · record -14.1°C–-5.6°C | 84mm | 11 | 63% | 2.7 m/s | 61% | 3 kWh/m² |
| Mar | 13.9°C · record 24.3°C–27.9°C | 2.6°C · record -10°C–-4.4°C | 68mm | 10 | 57% | 2.8 m/s | 56% | 4.3 kWh/m² |
| Apr | 19.3°C · record 24°C–33.1°C | 7.5°C · record -3.8°C–1.1°C | 84mm | 10 | 59% | 2.7 m/s | 59% | 5.3 kWh/m² |
| May | 23.1°C · record 28.8°C–32.9°C | 12.7°C · record 0.1°C–6.6°C | 129mm | 15 | 69% | 2.2 m/s | 67% | 5.4 kWh/m² |
| Jun | 28.2°C · record 32°C–36.5°C | 17.1°C · record 6.2°C–11.9°C | 102mm | 12 | 67% | 2.1 m/s | 60% | 6.3 kWh/m² |
| Jul | 31°C · record 34.2°C–36.9°C | 20.3°C · record 12.3°C–18°C | 114mm | 12 | 68% | 1.7 m/s | 57% | 6.1 kWh/m² |
| Aug | 29.3°C · record 32.7°C–36.5°C | 19°C · record 8.8°C–16.5°C | 99mm | 12 | 71% | 1.7 m/s | 57% | 5.3 kWh/m² |
| Sep | 25.8°C · record 27.6°C–37.3°C | 15.5°C · record 3.2°C–13.1°C | 105mm | 11 | 73% | 1.9 m/s | 56% | 4.2 kWh/m² |
| Oct | 20.3°C · record 25.3°C–33.9°C | 9°C · record -1.6°C–3.3°C | 77mm | 7 | 72% | 2.3 m/s | 48% | 3.5 kWh/m² |
| Nov | 13.2°C · record 21.3°C–27.5°C | 2.2°C · record -6.6°C–-3.3°C | 68mm | 8 | 64% | 2.4 m/s | 49% | 2.6 kWh/m² |
| Dec | 8°C · record 14.5°C–21.2°C | -0.9°C · record -16.7°C–-4.9°C | 82mm | 9 | 66% | 2.3 m/s | 61% | 2 kWh/m² |
"Avg high"/"Avg low" is the mean daily high/low for that month, averaged across every year on file. The "record" figure alongside it is a different statistic — the single hottest (or coldest) hour ever recorded during that month across all years — so it can sit above or below the average and does not describe the average's year-to-year spread. A "wet day" is any day with at least 1.0mm of rain.
Year to year
Annual average temperature, 2016–2025.
Across these 10 years, the annual average has moved by about +0.2°C per decade. That’s a short window for a reliable long-term climate trend — treat it as indicative, not definitive.
Annual rainfall has moved by about -301.3mm per decade over the same period.
2025 (the most recent year on file) averaged 13°C, below the 9-year baseline of 13.6°C by 1.4 standard deviations.
Typical extremes per year
Rainy days
124.3 days
≥1.0mm rain
Heavy rain days
12.7 days
≥20mm rain
Extreme heat days
0 days
daily high ≥40°C
Frost days
80.3 days
daily low ≤0°C
Averaged across 10 years on file. Thresholds match PastClimate's data pipeline definitions — see data & sources.
Records on file
Ranked across 10 years of data currently on file (2016–2025).
Hottest day
37.3°C
6 September 2023
2023 was 2.2 SD above the 9-year average that year
Coldest day
-21.3°C
22 January 2025
2025 was 1.4 SD below the 9-year average that year
Wettest day
69.4mm
28 July 2017
2017 was 0.02 SD above the 9-year average that year
Windiest day
9m/s
2 March 2018
2018 was 1.7 SD below the 9-year average that year
See the detail: Washington on 28 July 2017.
Nearby cities
Frequently asked questions about Washington's climate
What is the hottest month in Washington?
July is typically the warmest month in Washington, with an average high of 31°C. January is typically the coolest, averaging -3.4°C overnight.
How much does it rain in Washington?
Washington gets about 1094mm of rain a year on average, with roughly 32% of it falling in the three wettest months (May is typically the wettest, November the driest).
How many extremely hot or cold days does Washington have?
On average, Washington sees about 0 day(s) a year at or above 40°C and about 80.3 day(s) at or below 0°C, based on 10 years of data.
Is Washington getting warmer?
Across the 10 years on file (2016–2025), the annual average temperature has moved by about +0.15°C per decade. That's a short window for a reliable long-term climate trend — treat it as indicative, not definitive.
What is the hottest day on record for Washington?
The hottest day on file is 6 September 2023 at 37.3°C, out of 10 year(s) searched.
Data & provenance
↓ Download monthly CSVData source & coverage — ERA5 reanalysis, 2016–2025 (10 years)details
- Source
- ERA5 reanalysis, accessed via the Copernicus Climate Change Service (C3S) Climate Data Store
- Data type
- Reanalysis — a physically consistent reconstruction combining a forecast model with historical observations, not a live station reading or a forecast
- Coverage
- 2016–2025 (10 years) for United States
- Location
- Washington — 38.750°, -78.250°, ERA5 grid cell center, 8.8 km from requested point
- Time zone
- America/New_York
- What's shown here
- Monthly and annual averages, and dated extreme-value records, derived from an hourly base record.
- Spatial resolution
- 0.25° (~25 km) distributed grid — ERA5's native model resolution is finer; this is the publicly distributed regridded product
- Version / refreshed
- Methodology v2026.07 · data last refreshed December 31, 2025
- Limitations
- A model reconstruction, not a station observation — hyper-local extremes (a single storm cell, an urban heat pocket) can differ from a nearby gauge. See the full methodology.
- Attribution
- Generated using Copernicus Climate Change Service information
Cite this data
PastClimate (2026-07-20). Historical climate data for Washington, United States (38.75°N, 78.25°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Washington, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 20, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Washington, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 20, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Washington, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-20},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.