National Weather ServiceIllinoisSevere Thunderstorm WatchArchive to October 1, 2026
Severe Thunderstorm Watches in Illinois
The National Weather Service issued 21 severe thunderstorm watches for Illinois in 2025 and 41 a year on average in 2008-2025; in 2021-2025 it had the 10th most of any state. 2026 through September: 57, 43% above the average of 40 for those months in 2008-2025. St. Clair was covered most often (181 times since 2008).
How many severe thunderstorm watches does Illinois get?
Every severe thunderstorm watch that covered part of Illinois. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 57 |
| 2025 | 21 |
| 2024 | 41 |
| 2023 | 47 |
| 2022 | 27 |
| 2021 | 36 |
| 2020 | 27 |
| 2019 | 51 |
| 2018 | 25 |
| 2017 | 32 |
| 2016 | 35 |
| 2015 | 34 |
| 2014 | 42 |
| 2013 | 27 |
| 2012 | 56 |
| 2011 | 61 |
| 2010 | 65 |
| 2009 | 45 |
| 2008 | 60 |
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 |
|---|---|---|---|
| St. Clair | 181 | 27 | July 10, 2026 |
| Madison | 180 | 26 | July 4, 2026 |
| Monroe | 180 | 29 | July 10, 2026 |
| Will | 177 | 39 | August 21, 2026 |
| Grundy | 173 | 36 | August 21, 2026 |
| Shelby | 173 | 33 | June 16, 2026 |
| Calhoun | 172 | 26 | June 11, 2026 |
| La Salle | 172 | 37 | August 21, 2026 |
| Kankakee | 170 | 40 | August 21, 2026 |
| Kendall | 169 | 33 | August 21, 2026 |
| Fayette | 168 | 23 | July 26, 2026 |
| Jersey | 167 | 26 | June 11, 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.
What is a severe thunderstorm watch?
Severe thunderstorm watches come from the NWS Storm Prediction Center when storms with large hail or damaging winds are possible over a large area for several hours. 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.