Flash Flood Warning Issued for Boone and Winnebago Counties in Illinois

Source: NOAA · Northern Illinois

This alert is no longer in effect.

NOAA issued it on April 16, 2026, 4 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.

The National Weather Service has issued a Flash Flood Warning for Boone and Winnebago Counties in Illinois, effective until 2:30 AM CDT on April 16, 2026, due to heavy rain causing rapid-onset flooding.

Read this weather record in 30 seconds

Record type
Flash Flood Warning
Affected area
Northern Illinois
Issued
April 16, 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 4 months ago; use the issuing agency's live warning service for current conditions in Northern Illinois.

Flash Flood Warning in Northern Illinois

Alert Details

A Flash Flood Warning has been issued by the National Weather Service in Chicago for the specified areas. It is effective from 8:27 PM CDT on April 15, 2026, until 2:30 AM CDT on April 16, 2026.

Affected Areas

The warning affects Boone County in north central Illinois and Winnebago County in north central Illinois. Specific locations include Rockford, Belvidere, Loves Park, Machesney Park, Roscoe, South Beloit, Rockton, Poplar Grove, Rockford Airport, Candlewick Lake, Cherry Valley, Winnebago, Davis Junction, Pecatonica, Lake Summerset, Durand, Capron, Timberlane, New Milford, and Garden Prairie.

What You Should Do

Persons along creeks, drainage ditches, and other waterways should take immediate precautions to protect life and property. Avoid areas prone to flooding.

Expected Conditions

Doppler radar indicates thunderstorms producing heavy rain with a rainfall rate of 1 to 2 inches in 1 hour. Additional rainfall amounts of 1 to 2 inches are possible in the warned area. Portions of the area have already received between 2 and 3.5 inches of rain.

Timeline

The alert is effective from 8:27 PM CDT on April 15, 2026, and ends at 2:30 AM CDT on April 16, 2026.

Original source: NOAA Official Notice ↗

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Frequently Asked Questions

Common questions about this NWS weather alert.

What is this NWS weather alert about?
The National Weather Service has issued a Flash Flood Warning for Boone and Winnebago Counties in Illinois, effective until 2:30 AM CDT on April 16, 2026, due to heavy rain causing rapid-onset flooding.
Which agency issued this alert?
This alert was issued by NOAA. The original notice is available at the source link at the bottom of this article.
How severe is this alert?
This alert is classified as "high" severity. Take precautions and monitor for updates.
What area is affected?
This alert affects Northern Illinois. Check with NOAA for the most current geographic scope.
Where can I find more Weather Alerts updates?
Browse the full Weather Alerts feed on Areazine at areazine.com/weather/ for the latest updates from NOAA and other agencies.