Washington has an average annual temperature of
51.8°F
(across all 34 cities) with approximately
1314 mm of annual precipitation
and average humidity of 81%.
The warmest city is Richland
with average July highs of 103.8°F,
while Spokane
is the coldest with average January lows of 0°F.
This page covers 45 years of NASA POWER climate data (1981–2025)
including temperature, rainfall, humidity, wind speed, and solar radiation.
Aug is typically the warmest month across Washington with average highs around
89.6°F, while
Dec is the coldest with average lows near
18.9°F.
Nov is the wettest month with approximately
207 mm of rainfall on average.
Month
Max Temp
Min Temp
Avg Temp
Rain (mm)
Humidity
Wind (m/s)
Solar (kWh/m²)
Jan
51.3°F
19.4°F
35.2°F
186
91%
0.8
1.10
Feb
54.5°F
20.3°F
37.4°F
132
87%
0.8
1.90
Mar
62.4°F
26.8°F
44.6°F
136
84%
0.8
3.00
Apr
71.6°F
31.3°F
51.4°F
102
80%
0.8
4.30
May
79.5°F
36.7°F
58.1°F
74
77%
0.7
5.30
Jun
84.6°F
42.8°F
63.7°F
60
76%
0.7
5.90
Jul
88.7°F
47.8°F
68.4°F
25
73%
0.6
6.40
Aug
89.6°F
48.4°F
69.1°F
31
71%
0.6
5.50
Sep
85.5°F
42.3°F
63.9°F
57
73%
0.7
4.10
Oct
73.4°F
32.9°F
53.2°F
127
80%
0.7
2.40
Nov
58.6°F
25°F
41.9°F
207
89%
0.8
1.30
Dec
51.1°F
18.9°F
35.1°F
189
91%
0.8
0.90
📈 Washington Yearly Climate Trends
🌡️ Annual Temperature Trend
State-wide avg annual high & low · Last 10 years
📈 Washington Long-Term Climate Trends (1981–2025)
This chart shows how Washington's average temperatures have shifted across 45 years.
Use the range buttons to focus on recent decades or view the full historical record.
Data is averaged across all 34 cities in the state.
🌧️ Annual Precipitation Trend
State-wide avg annual precipitation · Last 10 years · mm/year
🔗 Explore Cities in Washington
Browse detailed weather history, monthly averages, and 45-year climate trends for every city in Washington.
Lake Stevens is the wettest city in Washington with approximately 1842 mm of annual precipitation on average. View Lake Stevens weather history →
What is the warmest month in Washington?▼
Aug is the warmest month across Washington, with state-wide average highs of 89.6°F and average lows of 48.4°F.
How many cities in Washington have weather data?▼
TownPillar has historical weather data for 34 cities in Washington, covering 45 years of NASA POWER climate records from 1981 to 2025.
Which month has the most sunshine in Washington?▼
Jul is the sunniest month across Washington with an average solar radiation of 6.40 kWh/m²/day state-wide. This solar radiation data from NASA POWER is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability.
Where does this climate data come from?▼
All data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis data. It includes monthly temperature, precipitation, humidity, wind speed, and solar radiation at 0.5° × 0.625° spatial resolution.
📚 Data Source
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources). Data covers 45 years (1981–2025) across 34 cities in Washington at monthly temporal resolution.