Flash Flood Warning Issued for Jo Daviess and Stephenson Counties in Illinois

Source: NOAA · Northwestern Illinois

This alert is no longer in effect.

NOAA issued it on April 15, 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.

A Flash Flood Warning is in effect for Jo Daviess and Stephenson Counties in Illinois until 2:00 AM CDT on April 15, 2026, due to thunderstorms producing heavy rain and potential flash flooding.

Read this weather record in 30 seconds

Record type
Flash Flood Warning
Affected area
Northwestern Illinois
Issued
April 15, 2026
Issuing authority
NWS Quad Cities

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 Northwestern Illinois.

Flash Flood Warning in Illinois

Alert Details

The National Weather Service has issued a Flash Flood Warning, effective from April 14, 2026, at 7:58 PM CDT until April 15, 2026, at 2:00 AM CDT.

Affected Areas

This warning affects Jo Daviess County and Stephenson County in northwestern Illinois.

What You Should Do

Turn around, don't drown when encountering flooded roads. Be especially cautious at night when it is harder to recognize the dangers of flooding. Do not attempt to cross flooded roads and find an alternate route. Please report observed flooding to local emergency services or law enforcement.

Expected Conditions

Doppler radar indicates thunderstorms producing heavy rain, with between 1 and 2 inches of rain already fallen and additional 1 to 2 inches possible. This will cause flash flooding of small creeks and streams, urban areas, highways, streets, underpasses, and other poor drainage and low-lying areas.

Timeline

The warning is effective from April 14, 2026, at 7:58 PM CDT and ends on April 15, 2026, at 2:00 AM CDT.

Original source: NOAA Official Notice ↗

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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.

Frequently Asked Questions

Common questions about this NWS weather alert.

What is this NWS weather alert about?
A Flash Flood Warning is in effect for Jo Daviess and Stephenson Counties in Illinois until 2:00 AM CDT on April 15, 2026, due to thunderstorms producing heavy rain and potential flash 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 Northwestern 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.