Historical weather data, all-time temperature records, and monthly climate averages for Lyons, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Lyons runs mild but unpredictable — the average high sits at 55° with a low around 37°, but this date has swung from a bitter 24° in 2018 all the way to a shirt-sleeve 78° in 2021. There's about a 1-in-3 chance of rain today, though snow is essentially off the table.
Lyons has seen some true extremes over the past three decades — from a scorching 104° on July 30, 1999 to a brutal -22° on January 30, 2019, a swing of 126 degrees. The wettest single day on record dropped 5.2 inches of rain in October 2017, and a December 2000 storm buried the area under 14.3 inches of snow.
Lyons peaks in summer with average highs of 85-86° in mid-July and bottoms out around 30° in mid-January. May is the wettest stretch of the year, so pack accordingly if you're visiting in spring. For the most comfortable outdoor weather, aim for late May through June or September, when highs are in the low-to-mid 70s.