Historical weather data, all-time temperature records, and monthly climate averages for Deerfield, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Deerfield is a classic transitional day — expect a high around 54° and a low near 35°, with nearly a 4-in-10 chance of rain. The date has swung wildly over the years, from a balmy 76° in 2005 to a bitter 21° low back in 2002. Snow? Not a real concern today.
Deerfield's weather has real teeth on both ends of the thermometer. The all-time high hit a punishing 104° on July 6, 2012, while January 30, 2019 brought a jaw-dropping -21° during the infamous polar vortex. The wettest single day on record dumped 4.53 inches on June 26, 2013.
Deerfield runs hot in summer and genuinely cold in winter — the warmest week of the year averages a high of 85° in late July, while mid-January bottoms out around 30°. May through September is your window for comfortable outdoor plans, with highs climbing from 70° to a peak of 84° in July. If you're visiting, pack an umbrella for late June and early July — that's the wettest stretch of the year, averaging over an inch of rain per week.