This alert expired on 2 September 2026 at 04:30 UTC. It is kept here as a record.
No stronger detection stands among the 46 recorded within 20 km of this point since 15 March 2026 — 2 others scored the same. The last comparable one was on 19 August 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 1 at 10:56PM CDT until September 1 at 11:30PM CDT by NWS Twin Cities/Chanhassen MN
Nearby, since 15 March 2026
- June 24, 2026 · score 22 · 9.9 km
- August 7, 2026 · score 22 · 11.1 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 23 out of 100, at 66 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | high |
| Calamity Score (ours) | 23 / 100 |
| Our confidence | 66% |
| Coordinates | 43.4524, -95.5699 |
| Nearest City | Sioux Falls (94 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-02T03:56:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.581f691ae2d3cfadd7c471b1c16f911e93f221e1.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Blue Earth, MN; Faribault, MN; Dickinson, IA; Lyon, IA; O'Brien, IA; Osceola, IA; Sioux, IA; Cottonwood, MN; Jackson, MN; Murray, MN; Nobles, MN; Rock, MN; Bon Homme, SD; Yankton, SD |
| Headline | Severe Thunderstorm Warning issued September 1 at 10:56PM CDT until September 1 at 11:30PM CDT by NWS Twin Cities/Chanhassen MN |
| Expires | 2026-09-01T23:30:00-05:00 |
| SenderName | NWS Twin Cities/Chanhassen MN |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.581f691ae2d3cfadd7c471b1c16f911e93f221e1.001.1","noaa_urn:oid:2.49.0.1.840.0.a09cb7f96e0b24c2b3c9d4dba93f52a484d81c75.001.1","noaa_urn:oid:2.49.0.1.840.0.b1e4fb57e766567a75613fe1ed4179a6ac6830a7.001.1"] |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | 2 NNW Orange City |
| Spc County | Sioux |
| Spc State | IA |
| Spc Comments | Report from social media. Time estimated from radar. (FSD) |
| MergedSources | [{"id":"spc_wind_43.37_-96.14_102","source":"spc","severity":"medium","severityValue":45,"timestamp":1788318720000,"latitude":43.37,"longitude":-96.14},{"id":"spc_wind_43.37_-96.13_103","source":"spc","severity":"medium","severityValue":45,"timestamp":1788320220000,"latitude":43.37,"longitude":-96.13},{"id":"spc_wind_43.36_-95.98_104","source":"spc","severity":"medium","severityValue":45,"timestamp":1788320520000,"latitude":43.36,"longitude":-95.98},{"id":"spc_hail_43.02_-96.07_136","source":"spc","severity":"high","severityValue":65,"timestamp":1788319080000,"latitude":43.02,"longitude":-96.07}] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 10 February 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 23/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.