Chicago, Illinois – Temperatures will plunge to near or below freezing again overnight, with a hard freeze expected by early Monday that could damage plumbing, kill plants, and create patchy frost on roads before the morning commute.
According to the National Weather Service in Chicago, a Freeze Warning takes effect at midnight and continues through 9 a.m. Monday across northern Illinois and northwest Indiana. A Frost Advisory remains in place through 9 a.m. Sunday morning, with temperatures near 32 degrees already producing frost across the region.
The coldest air will settle inland, where lows could drop to 27 degrees in areas like Rockford, DeKalb, and La Salle. The Chicago metro, including Cook County cities such as Evanston, Schaumburg, and Orland Park, is expected to bottom out closer to 30 degrees. Communities along I-90, I-88, I-55, and I-80—including Aurora, Joliet, Kankakee, and Gary—may see frost forming on bridges and overpasses before sunrise Monday.
The freeze poses a risk to early-season crops, backyard gardens, and exposed outdoor plumbing. Residents should cover or bring in plants, shut off outdoor water lines, and protect hoses. Those heading out early Monday should watch for slick spots, especially on elevated road surfaces.
Conditions will improve after 9 a.m. Monday as temperatures rise above freezing. Additional cold-weather alerts may follow if similar overnight conditions return early this week.
