Alert archive / North Dakota / Sioux County
Weather alerts in Sioux County, North Dakota, 2025
97 weather alerts in 2025, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Sioux County and its neighbors
Each county as a circle sized by its count in 2025. Tap one for its archive.
- Alerts
- 97
- Warnings
- 34
- Watches
- 18
- Advisories
- 1
- Busiest month
- June27 alerts
- Busiest day
- September 14, 20257 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
4 of 5 tornado warnings covering Sioux County in 2025 had a tornado report inside them.
Sioux County, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 5 | 4 | 20% | 0 | ||
| Severe thunderstorm warnings | 21 | 16 | 24% | 8 | 100% | 21 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2025
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Bismarck, ND: tornado warnings | 59 | 32 | 46% | 52 | 87% | 16 min |
| NWS Bismarck, ND: severe thunderstorm warnings | 280 | 160 | 43% | 420 | 88% | 26 min |
| NWS Bismarck, ND: flash flood warnings | 3 | 1 | 67% | 2 | 100% | 16 min |
An office's figures cover every county it serves, including across state lines.
Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.
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 | Lasted |
|---|---|---|---|
| Feb 7, 5:14 PM CST | Mesoscale Discussion | SPC | 4 hr |
| Mar 8, 3:24 AM CST | Fire Weather Watch | BIS | 23 hr |
| Mar 9, 3:13 AM CDT | Red Flag Warning | BIS | 41 hr |
| Apr 8, 12:56 PM CDT | Fire Weather Watch | BIS | 13 hr |
| Apr 9, 2:25 AM CDT | Red Flag Warning | BIS | 19 hr |
| Apr 10, 2:27 PM CDT | Red Flag Warning | BIS | 31 hr |
| May 3, 2:19 AM CDT | Fire Weather Watch | BIS | 24 hr |
| May 4, 1:56 AM CDT | Red Flag Warning | BIS | 19 hr |
| May 5, 2:16 PM CDT | Mesoscale Discussion | SPC | 89 min |
| May 5, 8:26 PM CDT | Special Weather Statement | BIS | 64 min |
| May 9, 1:59 PM CDT | Red Flag Warning | BIS | 31 hr |
| May 10, 1:18 PM CDT | Red Flag Warning | BIS | 56 hr |
| May 11, 5:28 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 11, 9:46 PM CDT | Special Weather Statement | BIS | 44 min |
| May 14, 2:00 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| May 16, 4:49 PM CDT | River Flood Warning | BIS | 17 hr |
| Jun 15, 10:30 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 15, 10:58 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 16, 1:28 AM CDT | Severe Thunderstorm Warning | BIS | 32 min |
| Jun 16, 1:40 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 16, 1:47 AM CDT | Severe Thunderstorm Warning | BIS | 43 min |
| Jun 16, 2:18 AM CDT | Severe Thunderstorm Warning | BIS | 57 min |
| Jun 17, 3:57 PM CDT | Special Weather Statement | BIS | 48 min |
| Jun 18, 5:03 PM CDT | Mesoscale Discussion | SPC | 117 min |
| Jun 18, 9:14 PM CDT | Special Weather Statement | BIS | 31 min |
| Jun 18, 10:29 PM CDT | Special Weather Statement | BIS | 31 min |
| Jun 19, 6:38 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 19, 9:41 PM CDT | Severe Thunderstorm Warning | BIS | 49 min |
| Jun 19, 10:28 PM CDT | Severe Thunderstorm Warning | BIS | 47 min |
| Jun 20, 3:24 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 20, 3:46 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 20, 6:14 PM CDT | Mesoscale Discussion | SPC | 91 min |
| Jun 20, 8:03 PM CDT | Severe Thunderstorm Warning | BIS | 57 min |
| Jun 20, 8:48 PM CDT | Severe Thunderstorm Warning | BIS | 27 min |
| Jun 20, 9:19 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Jun 22, 2:27 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 22, 8:41 AM CDT | Severe Thunderstorm Warning | BIS | 64 min |
| Jun 22, 9:17 AM CDT | Mesoscale Discussion | SPC | 88 min |
| Jun 25, 6:22 AM CDT | Special Weather Statement | BIS | 23 min |
| Jun 25, 6:57 AM CDT | Special Weather Statement | BIS | 33 min |
| Jun 27, 3:36 PM CDT | Mesoscale Discussion | SPC | 114 min |
| Jun 27, 5:20 PM CDT | Tornado Watch | SPC | 8 hr |
| Jun 27, 7:17 PM CDT | Mesoscale Discussion | SPC | 58 min |
| Jul 9, 2:47 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 9, 3:49 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Jul 9, 6:30 PM CDT | Mesoscale Discussion | SPC | 90 min |
| Jul 20, 5:09 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 20, 10:58 PM CDT | Mesoscale Discussion | SPC | 92 min |
| Jul 21, 12:29 AM CDT | Special Weather Statement | BIS | 46 min |
| Jul 21, 10:11 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 25, 7:39 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 25, 8:53 PM CDT | Mesoscale Discussion | SPC | 67 min |
| Jul 25, 11:24 PM CDT | Mesoscale Discussion | SPC | 96 min |
| Jul 26, 3:50 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 26, 7:52 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 26, 9:30 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 26, 10:19 PM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Jul 27, 12:27 AM CDT | Severe Thunderstorm Warning | BIS | 48 min |
| Jul 27, 1:49 AM CDT | Special Weather Statement | BIS | 26 min |
| Jul 28, 7:21 AM CDT | Mesoscale Discussion | SPC | 114 min |
| Jul 28, 8:31 AM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 28, 9:59 AM CDT | Severe Thunderstorm Warning | BIS | 61 min |
| Jul 28, 10:42 AM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 5, 5:33 AM CDT | Special Weather Statement | BIS | 27 min |
| Aug 5, 8:18 AM CDT | Special Weather Statement | BIS | 27 min |
| Aug 5, 8:44 AM CDT | Special Weather Statement | BIS | 31 min |
| Aug 5, 2:40 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 5, 4:03 PM CDT | Tornado Watch | SPC | 8 hr |
| Aug 7, 11:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 8, 12:34 AM CDT | Severe Thunderstorm Warning | BIS | 56 min |
| Aug 8, 1:12 AM CDT | Severe Thunderstorm Warning | BIS | 63 min |
| Aug 8, 1:18 AM CDT | Mesoscale Discussion | SPC | 87 min |
| Aug 16, 10:23 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 16, 10:59 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 17, 2:47 AM CDT | Mesoscale Discussion | SPC | 88 min |
| Aug 17, 2:59 AM CDT | Severe Thunderstorm Warning | BIS | 61 min |
| Aug 17, 3:56 AM CDT | Severe Thunderstorm Warning | BIS | 64 min |
| Aug 17, 4:31 AM CDT | Severe Thunderstorm Warning | BIS | 29 min |
| Sep 8, 5:29 PM CDT | Special Weather Statement | BIS | 31 min |
| Sep 8, 5:59 PM CDT | Special Weather Statement | BIS | 31 min |
| Sep 8, 6:30 PM CDT | Special Weather Statement | BIS | 30 min |
| Sep 12, 5:52 PM CDT | Severe Thunderstorm Warning | BIS | 38 min |
| Sep 12, 6:01 PM CDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 12, 6:24 PM CDT | Severe Thunderstorm Warning | BIS | 51 min |
| Sep 12, 6:39 PM CDT | Severe Thunderstorm Warning | BIS | 51 min |
| Sep 12, 7:55 PM CDT | Special Weather Statement | BIS | 35 min |
| Sep 12, 8:33 PM CDT | Areal Flood Advisory | BIS | 3 hr |
| Sep 12, 8:44 PM CDT | Special Weather Statement | BIS | 31 min |
| Sep 12, 9:49 PM CDT | Mesoscale Discussion | SPC | 116 min |
| Sep 14, 1:07 PM CDT | Tornado Watch | SPC | 8 hr |
| Sep 14, 1:13 PM CDT | Tornado Warning | BIS | 32 min |
| Sep 14, 1:41 PM CDT | Tornado Warning | BIS | 34 min |
| Sep 14, 1:46 PM CDT | Tornado Warning | BIS | 29 min |
| Sep 14, 2:13 PM CDT | Tornado Warning | BIS | 32 min |
| Sep 14, 2:25 PM CDT | Tornado Warning | BIS | 35 min |
| Sep 14, 2:44 PM CDT | Flash Flood Warning | BIS | 5 hr |
| Sep 16, 12:32 AM CDT | Special Weather Statement | BIS | 28 min |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20242026
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.