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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 States7:18 AM localChange location

Annual average

12.2°C

across all months

Warmest month

29.9°C

Jul average high

Coolest month

-3.6°C

Jan average low

Annual rainfall

1234mm

total per year

Washington is typically hottest in July and coolest in January, a swing of about 33.5°C across the year. About 28% of annual rainfall falls in the three wettest months (July is typically wettest, November driest).

Monthly averages

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

JanFebMarAprMayJunJulAugSepOctNovDec
Avg high Avg low Rainfall
MonthAvg highAvg lowRainfallWet daysHumidityWindCloudSolar
Jan3.6°C · record 8.9–17.9°C-3.6°C · record -18.4–-3.7°C91mm1064%3.3 m/s61%2 kWh/m²
Feb6.3°C · record 11.4–25°C-2.3°C · record -17.7–-10°C95mm1163%3.1 m/s63%2.9 kWh/m²
Mar10.6°C · record 16.1–26.1°C0.9°C · record -18–-4.2°C102mm1159%3.4 m/s58%4.1 kWh/m²
Apr16.2°C · record 20–31.6°C6°C · record -3.7–0.8°C111mm1260%3.2 m/s65%4.9 kWh/m²
May21.4°C · record 27.4–33.6°C11.4°C · record 0–7.3°C116mm1367%2.7 m/s68%5.4 kWh/m²
Jun26.7°C · record 31.6–36.5°C16.2°C · record 6.5–10.9°C92mm1166%2.5 m/s60%6.1 kWh/m²
Jul29.9°C · record 32.5–36°C19.9°C · record 12.4–17.8°C120mm1369%2.2 m/s58%6 kWh/m²
Aug28.2°C · record 29.9–35.1°C18.7°C · record 9.9–14.8°C112mm1271%2.2 m/s57%5.2 kWh/m²
Sep24.8°C · record 29.5–33.9°C15°C · record 4–9.9°C101mm1071%2.5 m/s57%4.1 kWh/m²
Oct18.7°C · record 23.5–33°C8.9°C · record -1.9–3.2°C101mm972%2.8 m/s53%3 kWh/m²
Nov11.5°C · record 18.5–26.7°C2.1°C · record -12.4–-3°C83mm965%3.1 m/s51%2.3 kWh/m²
Dec5.5°C · record 12.2–17.2°C-1.7°C · record -15.7–-4.8°C110mm1068%3 m/s63%1.7 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 +0.15°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 -83.48mm per decade over the same period.

2025 (the most recent year on file) averaged 11.790565483755195°C, below the 9-year baseline of 12.3°C by 1.45 standard deviations.

Typical extremes per year

Rainy days

130.5 days

≥1.0mm rain

Heavy rain days

14.9 days

≥20mm rain

Extreme heat days

0 days

daily high ≥40°C

Frost days

90.3 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

36.5°C

24 June 2025

2025 was 1.45 SD below the 9-year average that year

Coldest day

-18.4°C

31 January 2019

2019 was 1.56 SD below the 9-year average that year

Wettest day

90.2mm

1 September 2021

2021 was 0.56 SD above the 9-year average that year

Windiest day

7.9m/s

25 February 2019

2019 was 1.56 SD below the 9-year average that year

See the detail: Washington on 1 September 2021.

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 29.9°C. January is typically the coolest, averaging -3.6°C overnight.

How much does it rain in Washington?

Washington gets about 1234mm of rain a year on average, with roughly 28% of it falling in the three wettest months (July 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 90.3 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 24 June 2025 at 36.5°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 — 40.750°, -75.000°, ERA5 grid cell center, 2.0 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 (40.75°N, 75.00°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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