Flood Warning Issued for Boone, Lake, and McHenry Counties in Illinois
This alert is no longer in effect.
NOAA issued it on April 26, 2026, 3 months ago. Warnings of this kind stay in effect for hours to a few days, so this page is a historical record of what was issued, not a current warning. For conditions where you are right now, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia).
Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.
A Flood Warning is in effect for Boone, Lake, and McHenry counties in Illinois until 8:00 AM CDT on April 18, 2026, due to flooding from excessive rainfall.
Read this weather record in 30 seconds
- Record type
- Flood Warning
- Affected area
- Northern Illinois
- Issued
- April 26, 2026
- Issuing authority
- NWS Chicago IL
Flood notices turn on location and timing. Treat the named area as this record's scope; do not assume nearby counties, parishes, or waterways were included.
Record status: historical. It was issued 3 months ago; use the issuing agency's live warning service for current conditions in Northern Illinois.
Alert Details
A Flood Warning has been issued by NWS Chicago IL. It is effective from 1:54 AM CDT on April 18, 2026, until 8:00 AM CDT on the same day.
Affected Areas
The warning affects portions of north central and northeast Illinois, specifically Boone, Lake, and McHenry counties. Locations that may experience flooding include Waukegan, Buffalo Grove, Crystal Lake, North Chicago, Gurnee, Mundelein, Algonquin, Highland Park, Lake in the Hills, Round Lake Beach, McHenry, Belvidere, Vernon Hills, Woodstock, Zion, Huntley, Loves Park, Grayslake, Libertyville, and Lake Zurich.
What You Should Do
Take immediate precautions to protect life and property if you are along rivers, creeks, or other waterways. Turn around and do not drive through flooded roads, as most flood deaths occur in vehicles. Be especially cautious at night when flooding dangers are harder to recognize.
Expected Conditions
Flooding is occurring due to excessive rainfall, with up to 2 inches of rain having fallen. Roads and streets may be flooded, and area creeks and streams are already elevated, increasing the risk of further flooding due to additional rainfall.
Timeline
The alert is effective from 1:54 AM CDT on April 18, 2026, and will expire at 8:00 AM CDT on April 18, 2026.
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 (1,281 characters here).
Similar severity timing
Same severity (high) notices issued closest in time to April 26, 2026.
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