Reported by SPC today.
No stronger detection stands among the 60 recorded within 20 km of this point since 22 March 2026 — 15 others scored the same. The last comparable one was on 19 August 2026.
What the source measured
SPC reported: Wind 58 kt near 12 WSW Castle Rock, Butte, SD. (UNR)
How we know
Confirmed by 10 independent sources, including SPC.
Our own score for this event is 22 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 | medium |
| Calamity Score (ours) | 22 / 100 |
| Our confidence | 66% |
| Coordinates | 44.9200, -103.6600 |
| Nearest City | Rapid City (99 km) |
| Impact Tier | minor |
| Timestamp | 2026-08-30T21:44:00.000Z |
| Source | https://www.spc.noaa.gov/climo/reports/today.html |
Score Breakdown
Technical Details
| ReportType | wind |
| Speed | 58 |
| Location | 12 WSW Castle Rock |
| County | Butte |
| State | SD |
| Comments | (UNR) |
| Iem TypeSummary | G |
| Iem Magnitude | 58 |
| Iem Unit | mph |
| Iem City | 12 WSW Castle Rock |
| Iem County | Butte |
| Iem State | SD |
| Iem Wfo | UNR |
| MergedSources | [{"id":"iem_G_44.920_-103.660_1788130440000","source":"iem","severity":"low","severityValue":25,"timestamp":1788130440000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788127140000","source":"iem","severity":"low","severityValue":25,"timestamp":1788127140000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788128040000","source":"iem","severity":"low","severityValue":25,"timestamp":1788128040000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788129240000","source":"iem","severity":"low","severityValue":25,"timestamp":1788129240000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788129840000","source":"iem","severity":"low","severityValue":25,"timestamp":1788129840000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788127440000","source":"iem","severity":"low","severityValue":25,"timestamp":1788127440000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788125940000","source":"iem","severity":"low","severityValue":25,"timestamp":1788125940000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788128640000","source":"iem","severity":"low","severityValue":25,"timestamp":1788128640000,"latitude":44.92,"longitude":-103.66},{"id":"iem_G_44.920_-103.660_1788126240000","source":"iem","severity":"low","severityValue":25,"timestamp":1788126240000,"latitude":44.92,"longitude":-103.66}] |
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 22/100, near Rapid City (United States), based on data from spc. Source: Calamity.live, a platform aggregating real-time data from 191 scientific monitoring sources.