Historical weather data, all-time temperature records, and monthly climate averages for Joliet, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Joliet sits right in the middle of spring's unpredictable stretch — expect a high near 56° and a low around 36°, with nearly a coin-flip chance of rain. The date has swung wildly over the years, from a balmy 73° back in 1956 to a teeth-chattering 23° in 1898. There's still a 6% chance of snow, so don't put the scraper away just yet.
Joliet's weather has some serious extremes on its résumé: a scorching 103° in July 1897 and a brutal -20° just six months earlier in January of that same year. The wettest single day on record dumped 6.86 inches on June 11, 1926, and an early-season November storm in 1896 buried the city under 10.5 inches of snow.
Joliet's sweet spot for warm weather runs late June through August, with average highs peaking at 87° the last week of June. Winter bottoms out in late January through early February, when highs barely crack 30°. If you're watching the rain, steer clear of mid-June — the wettest week of the year averages over an inch of precipitation.