Chicago, Illinois – Drivers along the Lake Michigan shoreline could encounter visibility dropping to just 0.25 miles or less tonight, creating sudden hazards on major roads and lakefront routes through early Friday morning.
According to the National Weather Service in Chicago, a Dense Fog Advisory remains in effect until 6 a.m. Friday for Lake and Cook counties in Illinois, including Chicago, Evanston, Waukegan, Schaumburg, and Des Plaines. The same lake-driven fog is also affecting northwest Indiana, though advisories there expire earlier at 9 p.m. Thursday for Lake and Porter counties.
The thick fog is developing near the Lake Michigan shoreline and may expand farther inland after sunset, covering parts of the Chicago metro overnight. Drivers on Lake Shore Drive, I-94, and nearby suburban roadways could encounter rapidly changing visibility, especially near the water.
Harbors from Winthrop Harbor south to Michigan City are also under a marine advisory through early Friday. Visibility on the lake may fall to one-quarter nautical mile, making navigation difficult for boaters moving between Illinois and Indiana ports.
Transportation officials urge drivers to slow down, use low-beam headlights, and leave extra following distance. Boaters should ensure navigation lights are active and rely on radar or compass guidance when possible.
Conditions should gradually improve after sunrise Friday, though additional advisories could be issued overnight if the fog thickens farther inland.
