Flood Advisory — Lake County, Illinois
Minor flooding is expected — not severe enough for a warning, but potentially inconvenient or hazardous for travel.
Current Status
🌊 Active: Flood Advisory
Flood Advisory issued August 9 at 12:43PM CDT until August 9 at 3:45PM CDT by NWS Chicago IL
* WHAT...Flooding caused by excessive rainfall is expected. * WHERE...Lake IL County in northeastern Illinois... Southeastern McHenry County in northeastern Illinois... * WHEN...Until 345 PM CDT. * IMPACTS...Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Underpasses may be flooded. Roads and streets may be flooded. * ADDITIONAL DETAILS... - At 1243 PM CDT, Doppler radar indicated heavy rain due to thunderstorms. Minor flooding is ongoing or expected to begin shortly in the advisory area. Up to 2 inches of rain have fallen. - Additional rainfall amounts of 1 to 2 inches are expected over the area. This additional rain will result in minor flooding. - Some locations that will experience flooding include... Waukegan, Buffalo Grove, Crystal Lake, North Chicago, Gurnee, Mundelein, Algonquin, Highland Park, Lake in the Hills, Round Lake Beach, McHenry, Vernon Hills, Zion, Huntley, Grayslake, Libertyville and Lake Zurich. - http://www.
Effective August 9, 2026 at 1:43 PM ET · Expires August 9, 2026 at 4:45 PM ET
Event Details
Event Type
Flood Advisory
Severity
minor
Issued By
NWS Chicago IL
Expires
August 9, 2026 at 4:45 PM ET
Last Checked
1 minute ago
What To Do
📋 Official NWS Guidance
A Flood Advisory means minor flooding along waterways and other poor drainage areas is imminent or may already be occurring. Persons in the advisory area should use caution and avoid flood waters.
Also In Effect For
This same Flood Advisory also covers:
Other Active Alerts in Illinois
Severe Thunderstorm Watch
Severe Thunderstorm Warning
Severe Thunderstorm Watch
Severe Thunderstorm Warning
Flood Advisory
Severe Thunderstorm Warning
Get Flood Advisory Alerts for Lake County
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Frequently Asked Questions
What does a Flood Advisory mean for Lake County, Illinois?
Minor flooding is expected — not severe enough for a warning, but potentially inconvenient or hazardous for travel.
Is this Flood Advisory currently active?
Yes — this alert is active as of our last check (1 minute ago). It's set to expire August 9, 2026 at 4:45 PM ET.
How do I get notified about Flood Advisory alerts for Lake County?
Download StormCast free on Google Play and set Lake County, Illinois as one of your monitored locations. StormCast checks the NWS feed continuously and pushes alerts like this directly to your phone — even with the screen off.
What other areas does this alert cover?
This same Flood Advisory is also in effect for McHenry County.