Alert archive / Iowa / Severe Thunderstorm Warnings / 2026
Severe Thunderstorm Warnings in Iowa, September 2026
50 severe thunderstorm warnings in September 2026. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of severe thunderstorm warnings reaches back to 1986.
Severe Thunderstorm Warnings by county
Each county as a circle sized by its count in September 2026. Tap one for its archive.
- Severe Thunderstorm Warnings
- 50
- Busiest day
- September 15, 202615 severe thunderstorm warnings
Over time
By day
Days in UTC, the clock the archive keeps.
The alerts
Every alert, in the order issued. Times are local, Central Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 9:24 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Plymouth, Sioux | 51 min |
| Sep 1, 10:02 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, O'Brien, Osceola, Plymouth, Sioux | 43 min |
| Sep 1, 10:34 PM CDT | Severe Thunderstorm Warning | FSD | Dickinson, Lyon, O'Brien, Osceola, Sioux | 71 min |
| Sep 4, 2:30 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 45 min |
| Sep 4, 3:21 PM CDT | Severe Thunderstorm Warning | DMX | Butler, Grundy | 39 min |
| Sep 4, 4:10 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton | 35 min |
| Sep 4, 4:31 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 27 min |
| Sep 4, 4:35 PM CDT | Severe Thunderstorm Warning | ARX | Fayette, Winneshiek | 25 min |
| Sep 4, 5:13 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 30 min |
| Sep 4, 7:04 PM CDT | Severe Thunderstorm Warning | DVN | Delaware | 41 min |
| Sep 6, 10:45 AM CDT | Severe Thunderstorm Warning | DMX | Emmet | 24 min |
| Sep 6, 2:34 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Ida | 41 min |
| Sep 6, 2:37 PM CDT | Severe Thunderstorm Warning | DMX | Sac | 38 min |
| Sep 6, 3:45 PM CDT | Severe Thunderstorm Warning | DMX | Adams, Union | 45 min |
| Sep 6, 3:47 PM CDT | Severe Thunderstorm Warning | DMX | Calhoun, Carroll, Crawford, Sac | 43 min |
| Sep 6, 3:51 PM CDT | Severe Thunderstorm Warning | OAX | Harrison, Shelby | 39 min |
| Sep 6, 4:13 PM CDT | Severe Thunderstorm Warning | DMX | Calhoun, Carroll, Greene, Webster | 47 min |
| Sep 7, 11:42 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 48 min |
| Sep 8, 5:50 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Jasper, Marshall, Polk, Story | 40 min |
| Sep 8, 6:21 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Mahaska, Marion, Polk, Poweshiek, Warren | 39 min |
| Sep 8, 6:55 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Lucas, Mahaska, Marion, Monroe, Polk and 2 more | 50 min |
| Sep 8, 8:18 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Iowa, Johnson, Keokuk, Linn, Washington | 57 min |
| Sep 8, 9:07 PM CDT | Severe Thunderstorm Warning | DVN | Cedar, Johnson, Jones, Linn, Muscatine | 46 min |
| Sep 11, 7:48 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 22 min |
| Sep 11, 9:24 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Sioux | 51 min |
| Sep 11, 10:29 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Ida, Plymouth, Woodbury | 46 min |
| Sep 14, 3:32 PM CDT | Severe Thunderstorm Warning | DMX | Bremer | 28 min |
| Sep 14, 5:56 PM CDT | Severe Thunderstorm Warning | OAX | Monona | 14 min |
| Sep 14, 6:52 PM CDT | Severe Thunderstorm Warning | OAX | Mills, Montgomery, Pottawattamie | 38 min |
| Sep 14, 6:57 PM CDT | Severe Thunderstorm Warning | OAX | Fremont, Mills | 48 min |
| Sep 14, 7:22 PM CDT | Severe Thunderstorm Warning | OAX | Mills, Montgomery, Pottawattamie, Shelby | 38 min |
| Sep 14, 7:32 PM CDT | Severe Thunderstorm Warning | OAX | Montgomery | 43 min |
| Sep 14, 7:40 PM CDT | Severe Thunderstorm Warning | DMX | Adair, Audubon, Cass, Guthrie | 50 min |
| Sep 14, 7:44 PM CDT | Severe Thunderstorm Warning | OAX | Fremont | 46 min |
| Sep 14, 8:17 PM CDT | Severe Thunderstorm Warning | OAX | Fremont, Page | 43 min |
| Sep 14, 8:24 PM CDT | Severe Thunderstorm Warning | DMX | Adair, Adams, Cass, Dallas, Guthrie, Madison and 1 more | 51 min |
| Sep 14, 8:44 PM CDT | Severe Thunderstorm Warning | OAX | Montgomery, Page | 46 min |
| Sep 14, 9:36 PM CDT | Severe Thunderstorm Warning | OAX | Fremont | 39 min |
| Sep 14, 9:58 PM CDT | Severe Thunderstorm Warning | OAX | Fremont, Montgomery, Page | 49 min |
| Sep 15, 12:07 AM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 23 min |
| Sep 15, 12:22 AM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 38 min |
| Sep 15, 12:38 AM CDT | Severe Thunderstorm Warning | OAX | Harrison, Pottawattamie | 37 min |
| Sep 15, 12:54 AM CDT | Severe Thunderstorm Warning | OAX | Harrison, Pottawattamie, Shelby | 66 min |
| Sep 15, 1:43 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Audubon, Cass, Guthrie | 32 min |
| Sep 15, 2:01 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Guthrie | 29 min |
| Sep 19, 6:52 PM CDT | Severe Thunderstorm Warning | DMX | Decatur, Ringgold | 38 min |
| Sep 19, 7:23 PM CDT | Severe Thunderstorm Warning | DMX | Decatur, Wayne | 37 min |
| Sep 19, 7:30 PM CDT | Severe Thunderstorm Warning | DMX | Decatur, Wayne | 30 min |
| Sep 20, 1:18 AM CDT | Severe Thunderstorm Warning | DVN | Cedar, Henry, Jefferson, Johnson, Keokuk, Louisa and 3 more | 57 min |
| Sep 20, 2:21 AM CDT | Severe Thunderstorm Warning | DVN | Clinton, Muscatine, Scott | 27 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Pottawattamie County6
- Lyon County5
- Sioux County5
- Montgomery County5
- Fremont County5
- Plymouth County4
- Adair County4
- Guthrie County4
- Clayton County3
- Harrison County3
- Shelby County3
- Jasper County3
- Polk County3
- Johnson County3
- Muscatine County3
- Mills County3
- Cass County3
- Page County3
- Decatur County3
- O'Brien County2
- Osceola County2
- Allamakee County2
- Cherokee County2
- Ida County2
- Sac County2
- Adams County2
- Union County2
- Calhoun County2
- Carroll County2
- Mahaska County2
- Marion County2
- Poweshiek County2
- Warren County2
- Keokuk County2
- Linn County2
- Washington County2
- Cedar County2
- Audubon County2
- Wayne County2
- Dickinson County1
30 more counties
- Butler County1
- Grundy County1
- Fayette County1
- Winneshiek County1
- Delaware County1
- Emmet County1
- Buena Vista County1
- Crawford County1
- Greene County1
- Webster County1
- Boone County1
- Marshall County1
- Story County1
- Lucas County1
- Monroe County1
- Benton County1
- Iowa County1
- Jones County1
- Woodbury County1
- Bremer County1
- Monona County1
- Dallas County1
- Madison County1
- Ringgold County1
- Henry County1
- Jefferson County1
- Louisa County1
- Van Buren County1
- Clinton County1
- Scott County1
Nearby
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.