Chicago, IL – Temperatures will سقوط quickly overnight, reaching 33°F by daybreak Sunday and triggering widespread frost that could damage plants and disrupt early morning routines across northern Illinois and northwest Indiana.
According to the National Weather Service in Chicago, a Frost Advisory is in effect from midnight CDT (1 a.m. EDT) to 9 a.m. CDT (10 a.m. EDT) Sunday. A more serious Freeze Watch follows late Sunday night through Monday morning, when lows could plunge to 28°F across the region.
The coldest readings are expected just before sunrise in Chicago’s suburbs and outlying cities including Rockford, Joliet, Naperville, and Waukegan, as well as northwest Indiana communities like Gary, Valparaiso, and Rensselaer. Patchy frost will form on exposed surfaces, with reduced visibility possible from shallow ground fog in rural areas. While major highways like I-90, I-88, and I-55 should remain clear, early drivers may need extra time to defrost windshields.
The greater threat arrives late Sunday night, when a hard freeze could kill unprotected vegetation and damage outdoor plumbing. Residents should cover or bring in plants, drain hoses, and insulate exposed pipes. Agricultural areas from DeKalb County to Kankakee and into Benton County, Indiana, face the highest crop risk.
Conditions improve after 10 a.m. Sunday, but another sharp temperature drop begins after sunset. Additional alerts may be issued as confidence increases in the Monday morning freeze.
