St. Clair County Climate
St. Clair County, Missouri
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
55.8°F
Annual Precip
43.4"
Annual Snowfall
9.9"
Extreme Heat Days
42
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
6b
Minimum winter temperature range for plant survival
4,183
Excellent for heat-loving crops
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: St. Clair County
Climate Verdict
St. Clair County has a mild, with an average annual temperature of 55.8°F, moderately wet with 43.4 inches of annual precipitation, occasional hot days — 41.650000000000006 per year above 90°F, light snow averaging 9.9 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are cold, with January averaging 31.1°F. summers are warm — July averages 78.8°F. The 48°F seasonal variation provides noticeable but manageable change.
Outdoor & Gardening Guidance
The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.
Regional Context
St. Clair County closely matches the Missouri statewide average temperature of 54.9°F.
Climate Profile
About St. Clair County Weather
Temperate Peaks in the Ozark Foothills
St. Clair County averages 55.8°F annually, leaning toward the warmer end of the national temperate spectrum. The climate is defined by long, humid summers and relatively short winters.
Warmer and Drier Than Peers
The county's 55.8°F average temperature puts it nearly a full degree above the Missouri state average. Its 43.4 inches of annual precipitation slightly trails the state benchmark of 43.8 inches.
Rising Heat in Western Missouri
St. Clair stands out with 42 days of extreme heat per year, more than many of its eastern neighbors. Despite the heat, it maintains a winter average of 33.9°F, providing a distinct seasonal break.
A Heavy Lean Toward Summer
July averages reach 78.8°F, fueled by frequent 90-degree days. Winter brings only 9.9 inches of snow annually, making for relatively mild cold seasons compared to the state's northern counties.
Prioritize Cooling and Drought Resistance
With 42 extreme heat days, efficient air conditioning is a primary utility concern for residents. Landscape choices should account for the slightly lower precipitation and high summer evaporation rates.
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.