Chicago, Ill. – The skies over Lake Michigan are crystal clear early this Thursday morning, the kind of calm that often hides a chill. Across the Chicago metro, the first widespread frost of the season is likely by Friday morning, signaling a firm shift toward late fall.
According to the National Weather Service in Chicago/Romeoville, a Frost and Freeze Risk extends across northern Illinois and northwest Indiana, including Cook, DuPage, Lake, and Will Counties. Under calm winds and clear skies, temperatures will tumble into the low to mid-30s, especially away from the city core. Areas north and west of I-55 and along I-80 are most likely to see early frost formation.
Gardeners should take precautions now — cover tender vegetation and bring in potted plants. Sensitive crops or outdoor plumbing could be damaged if left unprotected. The cold air settles briefly, with Friday’s highs recovering only into the mid-50s under sunny skies.
Saturday continues crisp but quiet, ideal for outdoor cleanups or Halloween decorating, with highs near 57°F and light winds. Sunday warms slightly into the upper 50s, but another front may bring scattered clouds late in the day.
Looking ahead, early next week remains seasonably cool, with hints of another cold push by Tuesday. While snow isn’t yet on the radar, the pattern is turning classic November — chilly nights, bright days, and an unmistakable winter edge to the air now moving over Chicagoland.
Five-Day Outlook for Chicago, IL:
Thu: 53/41 – Mostly sunny; breezy at times.
Fri: 54/42 – Early frost possible; sunny and cool.
Sat: 57/44 – Mostly sunny; calm.
Sun: 59/49 – Partly sunny; milder.
Mon: 54/48 – Increasing clouds; cooler late.
