Weather
Chicago, IL Weather Oct. 23: Dense Fog Possible, Highs Near 76°
Chicago, IL – Residents across Chicago and northeastern Illinois should prepare for the possibility of patchy fog early Friday morning, Oct. 23, before another stretch of unusually warm late October w
By Nora Whitfield · 2026-10-22T20:24:50.500Z
Chicago, IL – Residents across Chicago and northeastern Illinois should prepare for the possibility of patchy fog early Friday morning, Oct. 23, before another stretch of unusually warm late October weather brings afternoon temperatures into the 70s through the weekend.
According to the National Weather Service in Chicago, dry and unseasonably warm conditions will continue through early next week. However, patchy shallow fog could develop late Thursday night into early Friday morning, with some locations potentially experiencing locally dense conditions.
Friday, Oct. 23 — Morning Fog Possible
Overnight temperatures will fall between 43 and 49 degrees across the region, with lower 50s possible in Chicago.
Patchy fog could develop overnight, particularly across portions of far northeastern Illinois.
Drivers traveling during the Friday morning commute should remain alert for sudden reductions in visibility.
Once the fog dissipates, partly sunny skies and afternoon temperatures ranging from 70 to 76 degrees are expected.
Locations near Lake Michigan will remain cooler, with temperatures generally in the 60s along the immediate shoreline.
Saturday, Oct. 24 — Warm Weekend Continues
Saturday will bring another mild afternoon, with highs ranging from 70 to 76 degrees.
Areas near the Illinois shoreline could see temperatures closer to 65 to 70 degrees.
Overnight lows will range from 45 to 50 degrees across the region.
Sunday, Oct. 25 — Temperatures Approach 80 Degrees
Sunday is expected to be the warmest day of the forecast period, with highs reaching 73 to 78 degrees.
Partly sunny skies will continue, providing favorable conditions for outdoor activities and weekend travel.
Monday, Oct. 26 — Mild Weather Persists
Temperatures will remain above normal Monday, with highs ranging from 66 to 75 degrees.
Communities along the Illinois lakeshore could remain in the lower 60s.
What Residents Should Know
The primary short term travel concern is patchy fog Friday morning, especially across far northeastern Illinois.
Motorists encountering reduced visibility should slow down, increase following distance and use low beam headlights.
No significant rainfall or severe weather threats are highlighted in the current outlook.
Residents should monitor updated forecasts for changes in fog coverage and visibility.