National Weather ServiceIllinoisSevere Thunderstorm WarningArchive to October 1, 2026
Severe Thunderstorm Warnings in Illinois
The National Weather Service issued 704 severe thunderstorm warnings for Illinois in 2025 and 614 a year on average in 2008-2025; in 2021-2025 it had the 9th most of any state. 2026 through September: 1,027, 76% above the average of 584 for those months in 2008-2025. Cook was covered most often (586 times since 2008).
How many severe thunderstorm warnings does Illinois get?
Every severe thunderstorm warning that covered part of Illinois. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 1,027 |
| 2025 | 704 |
| 2024 | 872 |
| 2023 | 934 |
| 2022 | 545 |
| 2021 | 423 |
| 2020 | 483 |
| 2019 | 633 |
| 2018 | 476 |
| 2017 | 593 |
| 2016 | 456 |
| 2015 | 501 |
| 2014 | 453 |
| 2013 | 403 |
| 2012 | 647 |
| 2011 | 835 |
| 2010 | 660 |
| 2009 | 505 |
| 2008 | 934 |
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 |
|---|---|---|---|
| Cook | 586 | 152 | August 12, 2026 |
| Will | 503 | 129 | August 12, 2026 |
| Madison | 494 | 106 | August 22, 2026 |
| St. Clair | 462 | 102 | August 17, 2026 |
| Tazewell | 420 | 126 | September 15, 2026 |
| Fulton | 412 | 141 | August 22, 2026 |
| Sangamon | 409 | 129 | August 16, 2026 |
| Rock Island | 405 | 143 | September 20, 2026 |
| Pike | 395 | 75 | September 15, 2026 |
| Calhoun | 392 | 90 | July 11, 2026 |
| La Salle | 391 | 96 | August 22, 2026 |
| McLean | 382 | 115 | September 15, 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 severe thunderstorm warnings for Illinois in AreaZine's record
NWS St LouisWarningSeptember 20, 2026
Severe Thunderstorm Warning: Monroe and Jefferson, IL and MO
Expired 11:30 p.m. CDT, September 20, 2026
NWS St LouisWarningSeptember 15, 2026
Severe Thunderstorm Warning: Adams, Pike and Marion, IL and MO
Expired 7:00 p.m. CDT, September 15, 2026
NWS PaducahWarningSeptember 5, 2026
Severe Thunderstorm Warning: Saline and Williamson, IL
Expired 7:30 p.m. CDT, September 5, 2026
NWS Quad Cities IAWarningAugust 21, 2026
Severe Thunderstorm Warning: Carroll, Whiteside, Clinton and 1 more, IL and IA
Expired 8:00 p.m. CDT, August 21, 2026
NWS ChicagoWarningAugust 21, 2026
Severe Thunderstorm Warning: De Kalb, Lee and Ogle, IL
Expired 6:00 p.m. CDT, August 21, 2026
NWS Quad Cities IAWarningAugust 21, 2026
Severe Thunderstorm Warning: Carroll and Whiteside, IL
Expired 4:30 p.m. CDT, August 21, 2026
NWS ChicagoWarningAugust 21, 2026
Severe Thunderstorm Warning: Boone and Winnebago, IL
Expired 4:45 p.m. CDT, August 21, 2026
NWS ChicagoWarningAugust 21, 2026
Severe Thunderstorm Warning: De Kalb and Kane, IL
Expired 4:00 p.m. CDT, August 21, 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 severe thunderstorm warning?
A severe thunderstorm warning means a storm is producing, or is about to produce, hail one inch across or larger and/or winds of 58 mph or more. A warning means the hazard is happening, about to happen, or very likely: act now to protect people and property. The national record · Every warning type in Illinois.