Walla Walla climate — normals and trends
Walla Walla (United States) has a warm-summer mediterranean continental climate (Dsb) under the Köppen-Geiger classification. Its mean annual temperature is 9.7 °C and it receives 671 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (21.4 °C on average) and the coldest is January (-0.2 °C). Rainfall peaks in December.
Walla Walla averages 93 frost days, 30 hot days (≥ 30 °C) and 119 rainy days per year.
Walla Walla has warmed by +1.5 °C between 1940 and 2025, or +0.18 °C per decade. This trend is statistically significant.
The number of frost days there went from about 103 to 83 per year over the period.
The hottest day of the period reached 43.1 °C (on 29 June 2021) and the coldest -33.6 °C (on 21 December 1990).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
Walla WallaWashington
- coords
- 46.06°, -118.34°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
9.7°C
Average daily high
15.0°C
Average daily low
4.6°C
Annual rainfall
671mm
Sunshine / day
9.8h
Mean relative humidity
61%
Average peak wind
14.1km/h
Seasonal range
21.6°C
Frost days (< 0 °C)
93 d/yr
Hot days (≥ 30 °C)
30 d/yr
Rainy days (≥ 1 mm)
119 d/yr
Annual snowfall
110.8 cm
Average feels-like high
12.4 °C
Average feels-like low
1.3 °C
Average peak gust
36.0 km/h
Tropical nights (≥ 20 °C)
2 d/yr
Solar radiation
15.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.5 °C
since 1940
+0.2 °C per decade · r² = 0.33 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
43.1 °C
29 June 2021
Coldest day
-33.6 °C
21 December 1990
Wettest day
47 mm
20 May 2020
Windiest day
44.0 km/h
8 January 1990
Strongest gust
114.8 km/h
17 December 2025
Hottest feels-like
43.0 °C
29 June 2021
Coldest feels-like
-38.6 °C
21 December 1990
Snowiest day
16.2 cm
7 December 1948
Sunniest day
15.6 h
21 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 3.8 °C | +0.8 °C | 59 mm | -29 mm |
| Feb | 3.8 °C | -2.1 °C | 110 mm | +38 mm |
| Mar | 11.9 °C | +2.3 °C | 88 mm | +14 mm |
| Apr | 15.9 °C | +2.0 °C | 28 mm | -30 mm |
| May | 20.3 °C | +1.5 °C | 23 mm | -29 mm |
| Jun | 25.8 °C | +2.7 °C | 2 mm | -33 mm |
| Jul | 29.9 °C | +1.3 °C | 5 mm | -5 mm |
| Aug | 29.2 °C | +1.5 °C | 15 mm | +1 mm |
| Sep | 26.5 °C | +3.8 °C | 13 mm | -14 mm |
| Oct | 15.0 °C | -0.4 °C | 59 mm | +3 mm |
| Nov | 9.8 °C | +2.3 °C | 63 mm | -27 mm |
| Dec | 8.3 °C | +4.8 °C | 153 mm | +60 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Walla Walla?
Walla Walla has a warm-summer mediterranean continental climate (Köppen Dsb). Over 1940-2025, the average annual temperature is 9.7 °C and it receives 671 mm of precipitation per year.
What is the hottest day ever recorded in Walla Walla?
The hottest day measured in Walla Walla between 1940 and 2025 was 29 June 2021, reaching 43.1 °C.
What is the coldest day in Walla Walla?
The coldest day measured in Walla Walla between 1940 and 2025 was 21 December 1990, at -33.6 °C.
Does it snow in Walla Walla?
Yes. Walla Walla gets on average 110.8 cm of snow per year and has around 93 frost days.
Has the climate of Walla Walla warmed?
Yes: Walla Walla warmed by +1.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Walla Walla?
The wettest day measured in Walla Walla between 1940 and 2025 was 20 May 2020, with 47 mm of rain in 24 hours.
What was the windiest day in Walla Walla?
The windiest day measured in Walla Walla between 1940 and 2025 was 8 January 1990, with winds reaching 44.0 km/h.
What is the warmest month in Walla Walla?
The warmest month in Walla Walla is July (21.4 °C on average); the coldest is January (-0.2 °C).
How much does it rain in Walla Walla?
Walla Walla receives on average 671 mm of precipitation per year, spread over about 119 rainy days.
Is it sunny in Walla Walla?
Walla Walla gets on average 9.8 hours of sunshine per day, roughly 3,577 hours per year over 1940-2025.
What is the biggest single-day snowfall in Walla Walla?
The heaviest 24-hour snowfall measured in Walla Walla between 1940 and 2025 was 7 December 1948, with 16.2 cm.
Are there tropical nights in Walla Walla?
Yes: Walla Walla has on average 2 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Walla Walla?
In Walla Walla, between 1940 and 2025, the highest apparent temperature reached 43.0 °C on 29 June 2021, and the lowest was -38.6 °C on 21 December 1990.
Compare Walla Walla with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Walla Walla