Flood Warning Issued for Sangamon River in Cass and Mason Counties, IL

Source: NOAA · Cass and Mason Counties, Illinois

This alert is no longer in effect.

NOAA issued it on July 27, 2026, 3 weeks 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.

NWS Lincoln IL has issued a Flood Warning for the Sangamon River near Chandlerville affecting Cass and Mason Counties from late Monday night to Friday morning.

Read this weather record in 30 seconds

Record type
Flood Warning
Affected area
Cass and Mason Counties, Illinois
Issued
July 27, 2026
Issuing authority
NWS Lincoln 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 weeks ago; use the issuing agency's live warning service for current conditions in Cass and Mason Counties, Illinois.

Alert Details

Flood Warning issued by NWS Lincoln IL. Effective from 2026-06-20T19:14:00-05:00. Onset 2026-06-23T05:30:00-05:00. Expires 2026-06-21T11:15:00-05:00. Ends 2026-06-26T07:00:00-05:00.

Affected Areas

Sangamon River near Chandlerville affecting Mason and Cass Counties in Illinois.

What You Should Do

Persons with interests along this river need to remain aware of the latest forecasts and associated flood risk for their area. Stay tuned for further updates on this flooding situation.

Expected Conditions

Minor flooding is forecast. At 7:00 PM CDT Saturday the stage was 455.1 feet. The river is expected to rise above flood stage early Tuesday morning to a crest of 457.4 feet early Wednesday morning. Flood stage is 456.6 feet.

Timeline

From late Monday night to Friday morning.

Original source: NOAA Official Notice ↗

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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.

Frequently Asked Questions

Common questions about this NWS weather alert.

What is this NWS weather alert about?
NWS Lincoln IL has issued a Flood Warning for the Sangamon River near Chandlerville affecting Cass and Mason Counties from late Monday night to Friday morning.
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 Cass and Mason Counties, 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.