Special Marine Warning Issued for Lake Michigan Near Chicago
If you are in immediate danger, call emergency services now.
For real-time, official alerts and instructions for your exact location, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia) as applicable. This article is a data summary, not a substitute for the issuing agency's live warning.
Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.
NWS Chicago has issued a Special Marine Warning for nearshore and open waters of Lake Michigan until midnight CDT due to severe thunderstorms with 40-knot winds and large hail.
Read this weather record in 30 seconds
- Record type
- Special Marine Warning
- Affected area
- Lake Michigan near Illinois
- Issued
- September 5, 2026
- Issuing authority
- NWS Chicago IL
Marine notices apply to named waters or shoreline zones. They may not describe conditions on land, even when the nearest place name is the same.
Record status: publication date is recent, but current status is not stored on this page. Check the issuing agency's live warning service before acting because warnings can be updated, narrowed, or cancelled.
Alert Details
A Special Marine Warning has been issued by the National Weather Service Chicago IL. The alert is effective from September 4 at 10:39PM CDT until September 5 at 12:00AM CDT.
Affected Areas
The warning covers nearshore waters from Winthrop Harbor to Northerly Island IL, and open waters from Winthrop Harbor to Michigan City out to mid-lake, including zones LMZ740, LMZ741, LMZ777, and LMZ779.
What You Should Do
Move to safe harbor immediately as gusty winds and high waves are expected. Small craft could be damaged in briefly higher winds and suddenly higher waves.
Expected Conditions
Severe thunderstorms were located along a line extending from 17 nm northeast of Montrose Harbor to near Wilmette Harbor and extending eastward toward mid-lake, moving east at 30 knots. Hazards include wind gusts to 40 knots and large hail.
Timeline
The alert is in effect until midnight CDT on September 5.
Original source: NOAA Official Notice ↗
Related Weather Alerts
All Weather Alerts →Nationwide notices with similar length or severity timing 8
Two Areazine-derived peer sets for this NWS weather alert: nearest notices by body length and by same severity near the same agency date. Peers come from other categories so they are not the same-feed Related list above.
Similar body length
Nearest notices by article body length (928 characters here).
Similar severity timing
Same severity (high) notices issued closest in time to September 5, 2026.
Frequently Asked Questions
Common questions about this NWS weather alert.