Historical weather data, all-time temperature records, and monthly climate averages for Sycamore, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Sycamore sits in that transitional awkward zone — average highs of 52° with lows still dipping to 33°. The date has swung wildly over 60 years of records, from a 77° scorcher in 1991 down to a brutal 17° in 1975, so pack layers.
Sycamore earns its Midwest stripes with a 130-degree spread between its all-time extremes — 103° in August 1988 and -27° in January 1985. A single July day in 1996 dropped 8.09 inches of rain, and a February 2011 snowstorm buried the area under 15.7 inches in one shot.
Summer is the sweet spot, with highs peaking around 84–85° during the third week of July — the same week that tends to be the wettest, averaging 1.3 inches. Winters are genuinely cold, with mid-January highs barely cracking 26°. Spring and fall offer pleasant shoulder seasons, though expect a wide range of anything.