Washington County Climate
Washington County, Iowa
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
49.3°F
Annual Precip
38.1"
Annual Snowfall
29.6"
Extreme Heat Days
20
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
5b
Minimum winter temperature range for plant survival
3,155
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Washington County
Climate Verdict
Washington County has a cool, averaging 49.3°F annually, moderate rainfall of 38.1 inches per year, occasional hot days — 20.3 per year above 90°F, moderate snowfall of 29.6 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 20.8°F. summers are warm — July averages 74.1°F. Residents experience a substantial 53°F difference between winter and summer.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Washington County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Washington County closely matches the Iowa statewide average temperature of 48.0°F, it is somewhat wetter than average for Iowa.
Climate Profile
About Washington County Weather
Washington County's Four-Season Continental Climate
An annual average of 49.3°F places Washington County in the cooler half of the United States. The region experiences the sharp temperature swings typical of the Great Plains.
Average Temperatures with Extra Moisture
Washington's 49.3°F is slightly above the state average of 48.0°F. However, its 38.1 inches of annual precipitation makes it wetter than the 36.1-inch state norm.
Matching the Regional Temperature Profile
Washington County is slightly cooler than Warren County's 49.9°F but maintains similar precipitation patterns. It sees more snow than Van Buren County, averaging 29.6 inches per year.
Moderate Summers and Significant Snowfall
July averages 74.1°F with 20 days of extreme heat. Winter is characterized by nearly 30 inches of snow and a chilly January average of 20.8°F.
Plan for Rain and Snow
The combination of 38.1 inches of rain and 29.6 inches of snow requires robust home exterior maintenance. Waterproof boots and high-quality winter insulation are essential for the 20.8°F January lows.
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.