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Washington climate

Typical historical weather for Washington, United States, averaged across 10 years of hourly climate data. Pick a date for a specific day.

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WashingtonUnited States5:00 PM localChange location

Annual average

17.3°C

across all months

Warmest month

31.8°C

Jul average high

Coolest month

1.5°C

Jan average low

Annual rainfall

1260mm

total per year

Washington is typically hottest in July and coolest in January, a swing of about 30.3°C across the year. About 34% of annual rainfall falls in the three wettest months (August is typically wettest, October driest).

Monthly averages

Average daily high/low temperature (band) and monthly rainfall (bars).

JanFebMarAprMayJunJulAugSepOctNovDec
Avg high Avg low Rainfall
MonthAvg highAvg lowRainfallWet daysHumidityWindCloudSolar
Jan12°C · record 18.3°C25.4°C1.5°C · record -16.7°C-3.2°C95mm1067%3.3 m/s52%2.7 kWh/m²
Feb15.6°C · record 23.3°C28.2°C4.4°C · record -7.6°C-3°C87mm1068%3.4 m/s58%3.2 kWh/m²
Mar18.6°C · record 25.6°C30.4°C7.1°C · record -5.9°C1.3°C89mm1063%3.6 m/s56%4.5 kWh/m²
Apr23.1°C · record 27.4°C31.3°C11.3°C · record -1.8°C5.5°C89mm964%3.6 m/s50%5.8 kWh/m²
May26.3°C · record 30.3°C35.9°C16.4°C · record 4.6°C10.7°C122mm1372%3.1 m/s63%5.7 kWh/m²
Jun29.9°C · record 33°C36.8°C20.2°C · record 10.5°C16.3°C111mm1474%2.7 m/s61%6.2 kWh/m²
Jul31.8°C · record 33.9°C36.2°C22.9°C · record 14.3°C21.5°C149mm1878%2.6 m/s64%6 kWh/m²
Aug30.6°C · record 32.1°C35.5°C22°C · record 12.9°C20.3°C156mm1780%2.4 m/s62%5.3 kWh/m²
Sep28.2°C · record 31.6°C35.7°C19.3°C · record 7.6°C17.3°C124mm1179%2.8 m/s57%4.5 kWh/m²
Oct23.8°C · record 28.1°C35.3°C13°C · record -0.4°C8.2°C67mm775%2.9 m/s48%3.7 kWh/m²
Nov18.2°C · record 24.6°C28.2°C6.5°C · record -4.9°C-0.4°C73mm870%3 m/s47%2.9 kWh/m²
Dec14.1°C · record 21.5°C25.9°C3.2°C · record -8.6°C-1.9°C98mm971%3.1 m/s55%2.3 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.

20162018202020222024

Across these 10 years, the annual average has moved by about -0.3°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 -311.34mm per decade over the same period.

2025 (the most recent year on file) averaged 16.9°C, below the 9-year baseline of 17.4°C by 1.76 standard deviations.

Typical extremes per year

Rainy days

133.9 days

≥1.0mm rain

Heavy rain days

13.6 days

≥20mm rain

Extreme heat days

0 days

daily high ≥40°C

Frost days

38.1 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

36.8°C

25 June 2025

2025 was 1.76 SD below the 9-year average that year

Coldest day

-16.7°C

6 January 2018

2018 was 0.47 SD below the 9-year average that year

Wettest day

131.5mm

8 October 2016

2016 was 0.72 SD below the 9-year average that year

Windiest day

11.4m/s

14 September 2018

2018 was 0.47 SD below the 9-year average that year

See the detail: Washington on 8 October 2016.

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 31.8°C. January is typically the coolest, averaging 1.5°C overnight.

How much does it rain in Washington?

Washington gets about 1260mm of rain a year on average, with roughly 34% of it falling in the three wettest months (August is typically the wettest, October 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 38.1 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 -0.32°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 25 June 2025 at 36.8°C, out of 10 year(s) searched.

Data & provenance

↓ Download monthly CSV
Data 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 — 35.500°, -77.250°, ERA5 grid cell center, 18.6 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

Plain text
PastClimate (2026-07-18). Historical climate data for Washington, United States (35.50°N, 77.25°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
APA
PastClimate. (2026). Historical climate data for Washington, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 18, 2026, from https://www.pastclimate.com/
MLA
"Historical Climate Data for Washington, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 18, 2026, www.pastclimate.com.
BibTeX
@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 2026-07-18},
  url = {https://www.pastclimate.com/}
}

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