This alert expired on 10 August 2026 at 23:45 UTC. It is kept here as a record.
No stronger detection stands among the 257 recorded within 20 km of this point since 15 March 2026 — 42 others scored the same. Another comparable one was recorded here earlier the same day. 19 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 10 at 5:20PM MDT until August 10 at 5:45PM MDT by NWS Rapid City SD
An estimated 73,569 people live within 50 km of this point.
Nearby, since 15 March 2026
- July 8, 2026 · score 39 · 13.1 km
- June 2, 2026 · score 39 · 19.7 km
- July 3, 2026 · score 39 · 23.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 39 out of 100, at 78 % 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) | 39 / 100 |
| Our confidence | 78% |
| Coordinates | 43.9440, -103.3140 |
| Nearest City | Rapid City (17 km) |
| Population Exposed | 73.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-10T23:20:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Custer, SD; Pennington, SD |
| Headline | Severe Thunderstorm Warning issued August 10 at 5:20PM MDT until August 10 at 5:45PM MDT by NWS Rapid City SD |
| Expires | 2026-08-10T17:45:00-06:00 |
| SenderName | NWS Rapid City SD |
| HasExactCoords | true |
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.
Calamity.live data shows a weather event with CalamityScore 39/100, near Rapid City (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.