This alert expired on 21 June 2026 at 02:35 UTC. It is kept here as a record.
No stronger detection stands among the 17 recorded within 20 km of this point since 3 April 2026 — 6 others scored the same. Another comparable one was recorded here earlier the same day. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 20 at 8:25PM MDT until June 20 at 8:30PM MDT by NWS Billings MT
Nearby, since 3 April 2026
- June 8, 2026 · score 22 · 13.5 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 22 out of 100, at 70 % 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 | 70% |
| Coordinates | 45.0522, -105.8611 |
| Nearest City | Gillette (89 km) |
| Impact Tier | minor |
| Timestamp | 2026-06-21T02:25:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Powder River, MT |
| Headline | Severe Thunderstorm Warning issued June 20 at 8:25PM MDT until June 20 at 8:30PM MDT by NWS Billings MT |
| Expires | 2026-06-20T20:35:00-06:00 |
| SenderName | NWS Billings MT |
| HasExactCoords | true |
| Iem TypeSummary | G |
| Iem Magnitude | 64 |
| Iem Unit | mph |
| Iem City | 8 SSW Spotted Horse |
| Iem County | Campbell |
| Iem State | WY |
| Iem Wfo | UNR |
| Iem Remark | Measured on a personal weather station. |
| MergedSources | [{"id":"iem_G_44.470_-105.840_1782001320000","source":"iem","severity":"low","severityValue":25,"timestamp":1782001320000,"latitude":44.47,"longitude":-105.84},{"id":"iem_G_44.600_-105.910_1782003060000","source":"iem","severity":"low","severityValue":25,"timestamp":1782003060000,"latitude":44.6,"longitude":-105.91}] |
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 Gillette (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 191 scientific monitoring sources.