Historical weather data, all-time temperature records, and monthly climate averages for Belvidere, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in Belvidere runs chilly, with an average high of just 51° and a low that can still flirt with freezing at 32°. The date has seen wild swings over 75 years of records — from a balmy 78° in 2021 to a brutal 9° back in 1975. There's a 40% chance of rain today, though snow is nearly off the table at just 3%.
Belvidere knows how to deal in extremes — this is a place that has cooked at 105° in July 2012 and frozen at -31° in January 2019, a 136-degree spread between its worst moments. A single August day in 1987 dumped 5.7 inches of rain, and a late November storm in 2018 buried the area under nearly a foot of snow in 24 hours.
Summer is the sweet spot here, with mid-July highs averaging 85° — though that's also when you're most likely to get rained on, with about 1.3 inches falling in an average week. January is the season to avoid if you run cold, with average highs barely clearing 27°. Spring and fall offer a quick but pleasant shoulder season as temps swing 30+ degrees between months.