This alert expired on 2 July 2026 at 14:35 UTC. It is kept here as a record.
It is the 9th strongest of the 52 detections recorded within 20 km of this point since 17 May 2026. Another comparable one was recorded here earlier the same day. 33 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 2 at 9:25AM CDT until July 2 at 9:30AM CDT by NWS Sioux Falls SD
Nearby, since 17 May 2026
- June 28, 2026 · score 43 · 15.4 km
- August 11, 2026 · score 43 · 22.2 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 22 out of 100, at 71 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 22 / 100 |
| Our confidence | 71% |
| Coordinates | 43.1270, -96.3180 |
| Nearest City | Sioux Falls (57 km) |
| Impact Tier | minor |
| Timestamp | 2026-07-02T14:25:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.c1e934387e09aa20d8399f9bda1a942a4364f7e7.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Lyon, IA; O'Brien, IA; Osceola, IA; Sioux, IA |
| Headline | Severe Thunderstorm Warning issued July 2 at 9:25AM CDT until July 2 at 9:30AM CDT by NWS Sioux Falls SD |
| Expires | 2026-07-02T09:35:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| Iem TypeSummary | G |
| Iem Magnitude | 58 |
| Iem Unit | MPH |
| Iem City | 4 W Hospers |
| Iem County | Sioux |
| Iem State | IA |
| Iem Wfo | FSD |
| Iem Remark | Via personal weather station. |
| MergedSources | [{"id":"iem_G_43.060_-96.180_1783000200000","source":"iem","severity":"low","severityValue":25,"timestamp":1783000200000,"latitude":43.06,"longitude":-96.18},{"id":"iem_G_43.080_-96.170_1783000200000","source":"iem","severity":"low","severityValue":25,"timestamp":1783000200000,"latitude":43.08,"longitude":-96.17},{"id":"iem_G_42.590_-95.970_1782992400000","source":"iem","severity":"low","severityValue":25,"timestamp":1782992400000,"latitude":42.59,"longitude":-95.97},{"id":"iem_G_43.070_-95.980_1783000800000","source":"iem","severity":"low","severityValue":25,"timestamp":1783000800000,"latitude":43.07,"longitude":-95.98}] |
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 22/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.