Walla Walla County Climate
Walla Walla County, Washington
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
53.3°F
Annual Precip
15.8"
Annual Snowfall
5.8"
Extreme Heat Days
41
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
7a
Minimum winter temperature range for plant survival
3,019
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Walla Walla County
Climate Verdict
Walla Walla County has a mild, with an average annual temperature of 53.3°F, semi-arid conditions with only 15.8 inches of annual precipitation, occasional hot days — 41.06666666666667 per year above 90°F, light snow averaging 5.8 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are cold, with January averaging 35.5°F. summers are warm — July averages 74.4°F. The 39°F seasonal variation provides noticeable but manageable change. December is typically the coldest month and July the warmest.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Walla Walla County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Walla Walla County is 3.4°F warmer than the Washington statewide average of 49.9°F, it is also noticeably drier, receiving 22.7 inches less precipitation than the state average, the county experiences 23.07389961389962 more extreme heat days than the state average.
Climate Profile
About Walla Walla County Weather
A Warm and Sunny Eastern Hub
Walla Walla County’s average annual temperature of 53.3°F aligns closely with the national median. Its semi-arid climate offers significantly more warmth than the typical Washington profile.
One of Washington's Warmest Counties
With an average temperature of 53.3°F, this county is significantly warmer than the state average of 49.9°F. It represents the sunnier, drier side of the Cascade Range.
Drier and Hotter than Whitman
The county is quite dry, receiving just 15.8 inches of precipitation annually. It is warmer and sees far less snow than nearby Whitman County, which averages 25.6 inches of snowfall.
Intense Summer Heat and Moderate Winters
Residents endure 41 days of extreme heat above 90°F, with July averages reaching a balmy 74.4°F. Winters are comparatively mild for the region, averaging 36.5°F from December to February.
Plan for Long, Hot Summers
Central air conditioning and efficient irrigation are vital for the 41 days of extreme heat. With only 5.8 inches of snow, focus winter prep on insulation rather than heavy plowing equipment.
Frequently Asked Questions
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.