Historical weather data, all-time temperature records, and monthly climate averages for Charleston, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Charleston sits right in that classic spring transition zone — expect a high near 60° and a low around 39°, based on 128 years of data. The date has swung wildly, from a bitter 22° in 1920 to a shirt-sleeve 85° back in 1929. There's about a 1-in-3 chance of rain today, but snow? Essentially zero.
Charleston's weather has real teeth at the extremes — the thermometer has reached a scorching 110° in July 1936 and plunged to a brutal -27° in January 1994, a 137-degree swing over the station's history. A single day in June 1957 dropped 6.5 inches of rain, and a January 1982 snowstorm buried the town under a foot of snow in one shot.
Summer is the headliner here, with highs averaging 88° the week of July 9–15, while early January barely cracks 37°. If you're chasing rain, late April into early May is the wettest stretch, averaging over an inch of precipitation in a single week. Spring and fall offer the most comfortable travel windows, with pleasant highs in the 60s and 70s through April–May and again in September–October.