Historical weather data, all-time temperature records, and monthly climate averages for Jacksonville, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Jacksonville sits right in that classic spring transition zone — the average high of 59° feels mild, but the record books tell a wilder story. This date has seen everything from a scorching 87° in 1929 to a brutal 10° low back in 1920. There's a 38% chance of rain today, so keep an umbrella handy.
Jacksonville doesn't mess around at the extremes — 114° in July 1954 and -28° in February 1934 represent a jaw-dropping 142-degree spread in recorded temperatures. A single day in September 1993 dumped over 5 inches of rain, and a February snowstorm in 1900 buried the town under a foot of snow.
Summers are the headline here, with highs averaging 88° during the hottest week of mid-July, while January and February sit in the mid-30s to low 40s. If you're watching your umbrella budget, late April into early May is the wettest stretch of the year, averaging over an inch of precipitation per week. Spring and fall offer the most comfortable travel windows, with April highs in the mid-60s and October hovering around 68°.