Right now
The most recent data we hold from NOAA arrived 9 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 1 July 2026 at 09:45 UTC. It is kept here as a record.
It is the 9th strongest of the 37 detections recorded within 20 km of this point since 15 March 2026. The last comparable one was on 28 June 2026. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 1 at 3:40AM CDT until July 1 at 4:45AM CDT by NWS Sioux Falls SD
An estimated 171,544 people live within 50 km of this point.
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 86 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 43 / 100 |
| Our confidence | 86% |
| Coordinates | 43.7390, -96.9430 |
| Nearest City | Sioux Falls (28 km) |
| Population Exposed | 171.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-01T08:40:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.4c765e14b702bfb5e23338e1094373e70715a6db.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Lyon, IA; Pipestone, MN; Rock, MN; Lake, SD; Lincoln, SD; McCook, SD; Minnehaha, SD; Moody, SD; Turner, SD |
| Headline | Severe Thunderstorm Warning issued July 1 at 3:40AM CDT until July 1 at 4:45AM CDT by NWS Sioux Falls SD |
| Expires | 2026-07-01T04:45:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| Iem TypeSummary | G |
| Iem Magnitude | 64 |
| Iem Unit | MPH |
| Iem City | 2 ESE Larchwood |
| Iem County | Lyon |
| Iem State | IA |
| Iem Wfo | FSD |
| Iem Remark | Personal weather station reported gust of 64 mph at 3:05 am CDT. |
| MergedSources | [{"id":"iem_G_43.440_-96.400_1782893100000","source":"iem","severity":"low","severityValue":25,"timestamp":1782893100000,"latitude":43.44,"longitude":-96.4}] |
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 8 March 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.
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