Walla Walla, WA climate
Walla Walla has mild winters and warm summers, with very little rain. A typical July afternoon reaches 91°, a January night drops to 30°, and about 9 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Walla Walla feels like
Winter
Spring
Summer
Fall
Walla Walla weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 43° | 30° | 1.8" | 4.2" | 13 | 23° – 44° |
| February | 48° | 31° | 1.5" | 2.5" | 11 | 28° – 46° |
| March | 57° | 36° | 1.7" | 0 | 12 | 38° – 51° |
| April | 64° | 41° | 1.6" | 0 | 11 | 47° – 57° |
| May | 73° | 48° | 1.7" | 0 | 9 | 56° – 65° |
| June | 80° | 53° | 1.2" | 0 | 7 | 62° – 75° |
| July | 91° | 60° | 0.3" | 0 | 3 | 67° – 80° |
| August | 90° | 59° | 0.4" | 0 | 3 | 69° – 77° |
| September | 80° | 51° | 0.6" | 0 | 4 | 62° – 70° |
| October | 65° | 41° | 1.5" | 0 | 8 | 48° – 59° |
| November | 51° | 34° | 2.0" | 0.1" | 12 | 36° – 49° |
| December | 42° | 29° | 2.0" | 2.2" | 13 | 29° – 40° |
| Year | 65° | 43° | 16.4" | 9.0" | 105 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Walla Walla
Walla Walla gets 16 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 105 days a year.
About 219 frost-free days a year
In half of years the last 32° night comes by March 27 and the first one by October 31. That leaves about 219 frost-free days for gardens, longer than 82% of U.S. towns.
Heating and cooling a home in Walla Walla
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Walla Walla, 84% of that work is heating and 16% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Walla Walla and its neighbors
Walla Walla borders 3 towns with climate data. January nights across them vary by 0.0°. Walla Walla East has the coldest January nights (30°) and Garrett the hottest July afternoons (91°). Walla Walla’s January low is 30° and its July high 91°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Walla Walla compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Walla Walla averaged 1.5° warmer than the 1900s. The biggest change is in January (+4.1°). The shift is larger than in 71% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Walla Walla’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. January swings the most: between 1991 and 2020 its average temperature ranged from 23° to 44°. August is the most reliable, staying within 7°.
Common questions about Walla Walla’s climate
What is the coldest month in Walla Walla?
December, with a typical high of 42° and a low of 29°.
What is the hottest month in Walla Walla?
July, with a typical high of 91° and a low of 60°. About 42 days a year reach 90°.
How much snow does Walla Walla get?
About 9 inches in a normal winter, most of it in January.
When is the first frost in Walla Walla?
In half of years the first 32° night comes by October 31, and the last spring frost by March 27.
What is the rainiest month in Walla Walla?
December, with 2.0 inches of rain and melted snow. The year totals 16 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Walla Walla itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Mill Creek Dam, WA (3 mi, snow) and Walla Walla Rgnl Airport, WA (3 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.