Charleston, IL Weather & Climate Normals
Charleston's real weather, in one number
Charleston, IL scores 47/100 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.
Charleston's hottest and coldest months
Charleston's hottest month is Jul, averaging 77°F; its coldest is Jan, averaging 29°F, a 47.9°F swing across the year, one of the widest gaps in this dataset.
Charleston's weather across the year
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| Jan | 38°F | 21°F | 2.54in | 8.1in |
| Feb | 43°F | 25°F | 2.69in | 5.5in |
| Mar | 54°F | 34°F | 3.11in | 1.3in |
| Apr | 67°F | 44°F | 5.09in | 0.3in |
| May | 77°F | 54°F | 4.52in | 0in |
| Jun | 86°F | 63°F | 4.84in | 0in |
| Jul | 88°F | 66°F | 4.4in | 0in |
| Aug | 87°F | 64°F | 2.94in | 0in |
| Sep | 81°F | 57°F | 3.15in | 0in |
| Oct | 69°F | 46°F | 3.94in | 0in |
| Nov | 54°F | 35°F | 3.74in | 0.8in |
| Dec | 42°F | 26°F | 2.79in | 3in |
Apr, May, Jun, Sep, and Oct are the best time to see Charleston at its mildest; the rest of the year, plan around Jul's heat and Jan's cold.
Rain and snow in Charleston
Charleston averages 43.75in of precipitation a year across roughly 120 days with measurable rain or snow, and 19in of snow a year.
Where Charleston ranks
Charleston ranks 2674 of 4876 US cities in this dataset for comfort score, and 85 of 330 within IL. About 17,361 people live there.
If you need tomorrow's forecast, not the 30-year average
Everything above is a 30-year average from Charleston, IL US, 0.9 miles from Charleston, 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