This alert expired on 18 June 2026 at 20:00 UTC. It is kept here as a record.
No stronger detection stands among the 26 recorded within 20 km of this point since 14 June 2026 — 4 others scored the same. The last comparable one was on 14 June 2026. 5 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 18 at 3:20PM EDT until June 18 at 4:00PM EDT by NWS Charleston SC
An estimated 107,478 people live within 50 km of this point.
Nearby, since 14 June 2026
- June 14, 2026 · score 43 · 17.8 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 83 % 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 | 83% |
| Coordinates | 32.8917, -80.5242 |
| Nearest City | Summerville (35 km) |
| Population Exposed | 107.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-18T19:20:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.e5e58de0743c6a9e08d0426d0ff47200ff592b09.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Colleton, SC |
| Headline | Severe Thunderstorm Warning issued June 18 at 3:20PM EDT until June 18 at 4:00PM EDT by NWS Charleston SC |
| Expires | 2026-06-18T16:00:00-04:00 |
| SenderName | NWS Charleston SC |
| HasExactCoords | true |
| Iem TypeSummary | R |
| Iem Magnitude | 1.58 |
| Iem Unit | inch |
| Iem City | 2 NNW Charleston |
| Iem County | Charleston |
| Iem State | SC |
| Iem Wfo | CHS |
| Iem Remark | CoCoRaHS observer reported 1.58 inches in the past 90 minutes. |
| MergedSources | [{"id":"iem_R_32.810_-79.960_1781807400000","source":"iem","severity":"low","severityValue":25,"timestamp":1781807400000,"latitude":32.81,"longitude":-79.96}] |
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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Calamity.live data shows a weather event with CalamityScore 43/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.