St. Charles, MO Weather & Climate Normals
St. Charles's real weather, in one number
St. Charles, MO scores 48/100 on this site's reading of NOAA's own 30-year normals: strongly seasonal. Comfortable weather is limited to a shorter window; summers, winters, or precipitation swing wide. 5 of the year's 12 months average between 55 and 75°F, the range this site counts as mild.
St. Charles's hottest and coldest months
St. Charles's hottest month is Jul, averaging 78°F; its coldest is Jan, averaging 31°F, a 47.5°F swing across the year, one of the widest gaps in this dataset.
St. Charles's weather across the year
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| Jan | 40°F | 22°F | 2.74in | 4.3in |
| Feb | 45°F | 25°F | 2.86in | 2.6in |
| Mar | 55°F | 34°F | 3.63in | 0.5in |
| Apr | 67°F | 44°F | 5.11in | 0in |
| May | 76°F | 55°F | 5.45in | 0in |
| Jun | 84°F | 64°F | 4.35in | 0in |
| Jul | 88°F | 68°F | 4.2in | 0in |
| Aug | 87°F | 66°F | 4.07in | 0in |
| Sep | 80°F | 57°F | 3.08in | 0in |
| Oct | 69°F | 46°F | 3.5in | 0in |
| Nov | 55°F | 35°F | 3.73in | 0.1in |
| Dec | 44°F | 26°F | 2.99in | 1.5in |
Apr, May, Jun, Sep, and Oct are the best time to see St. Charles at its mildest; the rest of the year, plan around Jul's heat and Jan's cold.
Rain and snow in St. Charles
St. Charles averages 45.71in of precipitation a year across roughly 101 days with measurable rain or snow, and 9in of snow a year.
Where St. Charles ranks
St. Charles ranks 2305 of 4876 US cities in this dataset for comfort score, and 37 of 135 within MO. About 72,458 people live there.
If you need tomorrow's forecast, not the 30-year average
Everything above is a 30-year average from St Charles Elm Pt, MO US, 1.3 miles from St. Charles, not a prediction for any specific day.
More on how this is worked out
How the comfort score is calculated · Why some cities show no snow or rain figure