National Weather ServiceIllinoisFlood WatchArchive to October 1, 2026
Flood Watches in Illinois
The National Weather Service issued 42 flood watches for Illinois in 2025 and 52 a year on average in 2008-2025; in 2021-2025 it had the 3rd most of any state. 2026 through September: 125, 165% above the average of 47 for those months in 2008-2025. Lake was covered most often (146 times since 2008).
How many flood watches does Illinois get?
Every flood watch that covered part of Illinois. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 126 |
| 2025 | 42 |
| 2024 | 115 |
| 2023 | 65 |
| 2022 | 54 |
| 2021 | 21 |
| 2020 | 79 |
| 2019 | 75 |
| 2018 | 93 |
| 2017 | 105 |
| 2016 | 23 |
| 2015 | 34 |
| 2014 | 28 |
| 2013 | 63 |
| 2012 | 1 |
| 2011 | 22 |
| 2010 | 21 |
| 2009 | 45 |
| 2008 | 56 |
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
When in the year does Illinois get them?
Sum of 2008-2025; the busiest month is labelled.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
Where in Illinois?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Lake | 146 | 49 | October 2, 2026 |
| Rock Island | 137 | 50 | September 30, 2026 |
| Winnebago | 135 | 45 | September 20, 2026 |
| La Salle | 134 | 45 | September 21, 2026 |
| Henderson | 101 | 40 | September 23, 2026 |
| Hancock | 92 | 37 | September 24, 2026 |
| Whiteside | 90 | 33 | September 30, 2026 |
| Henry | 87 | 42 | September 30, 2026 |
| Iroquois | 85 | 28 | August 19, 2026 |
| Mercer | 81 | 33 | September 30, 2026 |
| Kane | 75 | 29 | September 19, 2026 |
| Grundy | 65 | 31 | September 19, 2026 |
The NWS issues these products for counties or forecast zones; a zone can be part of a county or a mountain range.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
The latest flood watches for Illinois in AreaZine's record
NWS Quad Cities IAWatchOctober 1, 2026
Flood Watch: Buchanan, Delaware, Dubuque and 22 more, IA and IL
In force until 1:00 a.m. CDT, October 2, 2026
NWS ChicagoWatchSeptember 30, 2026
Flood Watch: Lake, IL
In force until 7:00 p.m. CDT, October 3, 2026
This list is AreaZine's record of the NWS alert feed, kept since April 6, 2026; the counts above come from the complete IEM archive.
Source: National Weather Service alerts (api.weather.gov).
What is a flood watch?
A flood watch means conditions may lead to flooding in the coming day or days; it is not yet happening. A watch means the conditions for the hazard are possible or favourable, but it is not yet happening: be ready to act if a warning follows. The national record · Every warning type in Illinois.