St. Clair County Climate
St. Clair County, Missouri
Avg Annual Temp
55.8°F
Annual Precip
43.4"
Annual Snowfall
9.9"
Extreme Heat Days
41.650000000000006
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Seasonal Overview
National Comparison
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
What is the average temperature in St. Clair County?
How much rain does St. Clair County get?
Does it snow in St. Clair County?
How hot does St. Clair County get in summer?
How cold are winters in St. Clair County?
Track your own weather in St. Clair County
Ambient Weather personal weather stations give you hyperlocal climate data.
Sponsored
Data source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020.
Climate normals are 30-year averages of weather variables computed from 1991 to 2020. Station data is aggregated to county level using spatial averaging. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.