This alert expired on 13 July 2026 at 01:00 UTC. It is kept here as a record.
No stronger detection stands among the 48 recorded within 20 km of this point since 16 March 2026 — 16 others scored the same. Another comparable one was recorded here earlier the same day. 5 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued July 12 at 7:04PM EDT until July 12 at 9:00PM EDT by NWS Charleston SC
An estimated 257,257 people live within 50 km of this point.
Nearby, since 16 March 2026
- June 21, 2026 · score 43 · 2.2 km
- August 13, 2026 · score 43 · 11.3 km
- June 18, 2026 · score 43 · 11.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 out of 100, at 80 % 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) | 43 / 100 |
| Our confidence | 80% |
| Coordinates | 32.1200, -80.6605 |
| Nearest City | Hilton Head Island (11 km) |
| Population Exposed | 257.3K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-12T23:04:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.4dc4c803351121db50111f167b838a1f2b5fce61.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Coastal waters from Edisto Beach SC to Savannah GA out 20 NM; Coastal waters from Savannah GA to Altamaha Sound GA out 20 nm, including Grays Reef National Marine Sanctuary; Waters from Edisto Beach SC to Savannah GA extending from 20 to 60 NM; Waters from Savannah GA to Altamaha Sound GA extending from 20 to 60 NM |
| Headline | Special Marine Warning issued July 12 at 7:04PM EDT until July 12 at 9:00PM EDT by NWS Charleston SC |
| Expires | 2026-07-12T21:00:00-04:00 |
| SenderName | NWS Charleston SC |
| 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.
Want to know when something happens near Hilton Head Island?
Calamity.live data shows a weather event with CalamityScore 43/100, near Hilton Head Island (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.