Alert archive / Iowa / Severe Thunderstorm Warnings / 2021
Severe Thunderstorm Warnings in Iowa, August 2021
122 severe thunderstorm warnings in August 2021. 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 August 2021. Tap one for its archive.
- Severe Thunderstorm Warnings
- 122
- Busiest day
- August 24, 202121 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 |
|---|---|---|---|---|
| Aug 5, 8:57 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 48 min |
| Aug 5, 9:31 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 44 min |
| Aug 5, 10:04 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 41 min |
| Aug 6, 12:10 AM CDT | Severe Thunderstorm Warning | FSD | Woodbury | 35 min |
| Aug 6, 1:06 AM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 39 min |
| Aug 6, 1:36 AM CDT | Severe Thunderstorm Warning | FSD | Sioux | 24 min |
| Aug 7, 8:41 PM CDT | Severe Thunderstorm Warning | OAX | Mills, Pottawattamie | 49 min |
| Aug 7, 8:50 PM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 40 min |
| Aug 7, 9:24 PM CDT | Severe Thunderstorm Warning | OAX | Mills, Pottawattamie | 51 min |
| Aug 7, 10:38 PM CDT | Severe Thunderstorm Warning | OAX | Fremont | 52 min |
| Aug 7, 11:25 PM CDT | Severe Thunderstorm Warning | OAX | Fremont, Mills, Montgomery, Page | 36 min |
| Aug 8, 4:10 PM CDT | Severe Thunderstorm Warning | FSD | Osceola | 50 min |
| Aug 8, 4:50 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Dickinson, O'Brien, Osceola | 55 min |
| Aug 9, 12:29 AM CDT | Severe Thunderstorm Warning | DMX | Boone, Hamilton, Webster | 46 min |
| Aug 10, 12:50 PM CDT | Severe Thunderstorm Warning | DMX | Clarke | 25 min |
| Aug 10, 1:48 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Bremer, Butler | 42 min |
| Aug 10, 2:10 PM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Fayette, Winneshiek | 50 min |
| Aug 10, 2:14 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Bremer | 46 min |
| Aug 10, 2:43 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton, Fayette, Winneshiek | 62 min |
| Aug 10, 2:55 PM CDT | Severe Thunderstorm Warning | DVN | Buchanan | 50 min |
| Aug 10, 2:57 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk | 18 min |
| Aug 10, 3:00 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall, Poweshiek, Tama | 60 min |
| Aug 10, 3:07 PM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque | 23 min |
| Aug 10, 3:23 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton | 52 min |
| Aug 10, 3:25 PM CDT | Severe Thunderstorm Warning | DVN | Buchanan, Delaware, Linn | 50 min |
| Aug 10, 3:29 PM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque | 31 min |
| Aug 10, 3:49 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Buchanan, Iowa | 41 min |
| Aug 10, 3:56 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 64 min |
| Aug 10, 4:04 PM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque, Jackson, Jones, Linn | 56 min |
| Aug 10, 4:28 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Buchanan, Delaware, Linn | 36 min |
| Aug 10, 4:38 PM CDT | Severe Thunderstorm Warning | DVN | Cedar, Jackson, Jones, Linn | 52 min |
| Aug 10, 5:00 PM CDT | Severe Thunderstorm Warning | DVN | Clinton, Jackson, Jones | 45 min |
| Aug 11, 5:56 AM CDT | Severe Thunderstorm Warning | DVN | Des Moines, Lee | 19 min |
| Aug 11, 6:10 AM CDT | Severe Thunderstorm Warning | DVN | Des Moines, Henry, Lee | 20 min |
| Aug 11, 6:24 AM CDT | Severe Thunderstorm Warning | DVN | Des Moines | 22 min |
| Aug 11, 6:38 AM CDT | Severe Thunderstorm Warning | DVN | Des Moines, Louisa | 37 min |
| Aug 11, 4:26 PM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque | 49 min |
| Aug 11, 5:11 PM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque, Jackson, Jones | 49 min |
| Aug 12, 7:26 AM CDT | Severe Thunderstorm Warning | DVN | Van Buren | 33 min |
| Aug 20, 6:13 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Plymouth, Woodbury | 32 min |
| Aug 20, 6:31 PM CDT | Severe Thunderstorm Warning | FSD | Ida, Woodbury | 29 min |
| Aug 20, 9:05 PM CDT | Severe Thunderstorm Warning | DMX | Franklin, Wright | 55 min |
| Aug 20, 9:46 PM CDT | Severe Thunderstorm Warning | DMX | Hamilton, Webster, Wright | 44 min |
| Aug 24, 9:43 AM CDT | Severe Thunderstorm Warning | FSD | Lyon, Osceola | 47 min |
| Aug 24, 10:44 AM CDT | Severe Thunderstorm Warning | FSD | Dickinson, Osceola | 30 min |
| Aug 24, 12:26 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Hancock | 49 min |
| Aug 24, 12:51 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Franklin, Hancock, Wright | 54 min |
| Aug 24, 1:18 PM CDT | Severe Thunderstorm Warning | DMX | Butler | 57 min |
| Aug 24, 1:43 PM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Floyd | 47 min |
| Aug 24, 1:44 PM CDT | Severe Thunderstorm Warning | DMX | Butler | 31 min |
| Aug 24, 1:53 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Bremer | 67 min |
| Aug 24, 2:15 PM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Fayette | 60 min |
| Aug 24, 2:21 PM CDT | Severe Thunderstorm Warning | DVN | Buchanan | 39 min |
| Aug 24, 2:49 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Buchanan, Delaware, Jones, Linn | 56 min |
| Aug 24, 2:59 PM CDT | Severe Thunderstorm Warning | ARX | Clayton, Fayette | 61 min |
| Aug 24, 3:03 PM CDT | Severe Thunderstorm Warning | DVN | Buchanan, Delaware, Dubuque | 42 min |
| Aug 24, 3:28 PM CDT | Severe Thunderstorm Warning | DMX | Hamilton, Hardin, Marshall, Story | 47 min |
| Aug 24, 3:42 PM CDT | Severe Thunderstorm Warning | DVN | Delaware, Dubuque | 48 min |
| Aug 24, 4:03 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Grundy, Hardin, Marshall, Poweshiek, Tama | 57 min |
| Aug 24, 4:17 PM CDT | Severe Thunderstorm Warning | DVN | Dubuque, Jackson | 58 min |
| Aug 24, 5:01 PM CDT | Severe Thunderstorm Warning | DVN | Jackson | 59 min |
| Aug 24, 5:05 PM CDT | Severe Thunderstorm Warning | DVN | Benton, Iowa | 40 min |
| Aug 24, 5:23 PM CDT | Severe Thunderstorm Warning | DVN | Clinton, Scott | 37 min |
| Aug 24, 6:07 PM CDT | Severe Thunderstorm Warning | DVN | Cedar, Johnson, Linn | 38 min |
| Aug 25, 12:43 AM CDT | Severe Thunderstorm Warning | OAX | Mills, Pottawattamie | 47 min |
| Aug 25, 1:00 AM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 24 min |
| Aug 25, 1:16 AM CDT | Severe Thunderstorm Warning | OAX | Fremont, Mills | 44 min |
| Aug 25, 1:25 AM CDT | Severe Thunderstorm Warning | OAX | Mills, Montgomery, Pottawattamie | 50 min |
| Aug 25, 1:53 AM CDT | Severe Thunderstorm Warning | OAX | Fremont, Mills | 37 min |
| Aug 25, 1:58 AM CDT | Severe Thunderstorm Warning | OAX | Mills, Montgomery, Pottawattamie | 32 min |
| Aug 26, 6:26 AM CDT | Severe Thunderstorm Warning | OAX | Harrison, Monona | 34 min |
| Aug 26, 6:51 AM CDT | Severe Thunderstorm Warning | OAX | Harrison, Monona, Pottawattamie | 24 min |
| Aug 26, 7:19 AM CDT | Severe Thunderstorm Warning | OAX | Harrison, Monona, Shelby | 26 min |
| Aug 26, 7:42 AM CDT | Severe Thunderstorm Warning | OAX | Harrison, Monona, Shelby | 33 min |
| Aug 26, 8:18 AM CDT | Severe Thunderstorm Warning | DMX | Calhoun, Carroll, Crawford, Greene, Sac | 42 min |
| Aug 26, 2:16 PM CDT | Severe Thunderstorm Warning | DMX | Appanoose, Davis, Wapello | 44 min |
| Aug 26, 7:02 PM CDT | Severe Thunderstorm Warning | DMX | Audubon, Carroll | 28 min |
| Aug 26, 8:47 PM CDT | Severe Thunderstorm Warning | DMX | Mahaska, Poweshiek | 58 min |
| Aug 26, 9:21 PM CDT | Severe Thunderstorm Warning | DVN | Iowa, Keokuk | 39 min |
| Aug 26, 9:58 PM CDT | Severe Thunderstorm Warning | DVN | Keokuk | 47 min |
| Aug 26, 10:30 PM CDT | Severe Thunderstorm Warning | DMX | Emmet, Palo Alto | 45 min |
| Aug 26, 10:43 PM CDT | Severe Thunderstorm Warning | DVN | Keokuk, Washington | 47 min |
| Aug 26, 10:57 PM CDT | Severe Thunderstorm Warning | DVN | Jefferson, Washington | 48 min |
| Aug 26, 11:39 PM CDT | Severe Thunderstorm Warning | DVN | Jefferson, Washington | 31 min |
| Aug 26, 11:42 PM CDT | Severe Thunderstorm Warning | DMX | Emmet, Palo Alto | 33 min |
| Aug 27, 12:17 AM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 28 min |
| Aug 27, 12:34 AM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Sioux | 41 min |
| Aug 27, 1:09 AM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Lyon, O'Brien, Osceola, Plymouth, Sioux | 51 min |
| Aug 27, 1:25 AM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Ida, Plymouth, Woodbury | 50 min |
| Aug 27, 1:52 AM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, Dickinson, O'Brien, Osceola | 68 min |
| Aug 27, 2:00 AM CDT | Severe Thunderstorm Warning | FSD | Buena Vista | 60 min |
| Aug 27, 4:23 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Hancock | 52 min |
| Aug 27, 4:58 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Franklin, Hancock | 32 min |
| Aug 27, 6:52 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Fayette, Winneshiek | 38 min |
| Aug 27, 7:10 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Worth | 65 min |
| Aug 27, 7:29 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton, Winneshiek | 46 min |
| Aug 27, 8:03 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 42 min |
| Aug 27, 8:09 PM CDT | Severe Thunderstorm Warning | ARX | Mitchell | 25 min |
| Aug 27, 8:15 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Worth | 30 min |
| Aug 28, 4:23 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 37 min |
| Aug 28, 5:00 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 45 min |
| Aug 28, 5:26 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Osceola | 34 min |
| Aug 28, 5:29 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Osceola | 31 min |
| Aug 28, 5:34 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 17 min |
| Aug 28, 6:44 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 46 min |
| Aug 28, 6:53 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 52 min |
| Aug 28, 7:23 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 52 min |
| Aug 28, 8:52 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Osceola, Sioux | 23 min |
| Aug 28, 9:13 PM CDT | Severe Thunderstorm Warning | FSD | Dickinson, Lyon, O'Brien, Osceola, Sioux | 47 min |
| Aug 30, 7:29 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Sioux | 46 min |
| Aug 30, 9:49 PM CDT | Severe Thunderstorm Warning | FSD | Ida | 26 min |
| Aug 30, 9:58 PM CDT | Severe Thunderstorm Warning | DMX | Carroll, Crawford, Sac | 62 min |
| Aug 30, 10:05 PM CDT | Severe Thunderstorm Warning | FSD | Ida | 10 min |
| Aug 30, 10:49 PM CDT | Severe Thunderstorm Warning | OAX | Monona | 26 min |
| Aug 30, 10:50 PM CDT | Severe Thunderstorm Warning | DMX | Carroll, Crawford | 55 min |
| Aug 30, 10:58 PM CDT | Severe Thunderstorm Warning | DMX | Audubon, Carroll, Crawford, Greene, Guthrie | 62 min |
| Aug 30, 11:29 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Marshall, Polk, Story | 46 min |
| Aug 30, 11:50 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall | 40 min |
| Aug 30, 11:54 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Madison, Marion, Polk, Warren | 36 min |
| Aug 31, 12:07 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Audubon, Cass, Guthrie | 38 min |
| Aug 31, 12:15 AM CDT | Severe Thunderstorm Warning | OAX | Harrison | 26 min |
| Aug 31, 1:35 AM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 25 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Lyon County17
- Sioux County11
- Osceola County10
- Delaware County10
- Pottawattamie County9
- Mills County8
- Dubuque County8
- Buchanan County7
- Linn County6
- Jackson County6
- Cerro Gordo County6
- Black Hawk County5
- Fayette County5
- Allamakee County5
- Clayton County5
- Marshall County5
- Jones County5
- Plymouth County5
- Harrison County5
- Monona County5
- Carroll County5
- Woodbury County4
- Fremont County4
- Dickinson County4
- O'Brien County4
- Winneshiek County4
- Benton County4
- Des Moines County4
- Cherokee County4
- Ida County4
- Hancock County4
- Crawford County4
- Montgomery County3
- Hamilton County3
- Bremer County3
- Butler County3
- Chickasaw County3
- Jasper County3
- Poweshiek County3
- Iowa County3
45 more counties
- Franklin County3
- Wright County3
- Audubon County3
- Keokuk County3
- Washington County3
- Clay County2
- Boone County2
- Webster County2
- Tama County2
- Cedar County2
- Clinton County2
- Lee County2
- Hardin County2
- Story County2
- Shelby County2
- Greene County2
- Sac County2
- Emmet County2
- Palo Alto County2
- Jefferson County2
- Buena Vista County2
- Worth County2
- Guthrie County2
- Polk County2
- Page County1
- Clarke County1
- Henry County1
- Louisa County1
- Van Buren County1
- Floyd County1
- Grundy County1
- Scott County1
- Johnson County1
- Calhoun County1
- Appanoose County1
- Davis County1
- Wapello County1
- Mahaska County1
- Mitchell County1
- Dallas County1
- Madison County1
- Marion County1
- Warren County1
- Adair County1
- Cass County1
Nearby
Alerts in force nowTornadoes on recordThe radar archive20202022
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. Rebuilt daily.