This alert expired on 4 July 2026 at 03:00 UTC. It is kept here as a record.
No stronger detection stands among the 240 recorded within 20 km of this point since 12 March 2026 — 159 others scored the same. The last comparable one was on 23 June 2026. 9 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Watch issued July 3 at 5:16PM EDT until July 3 at 11:00PM EDT by NWS Upton NY
An estimated 3,327,294 people live within 50 km of this point.
Nearby, since 12 March 2026
- March 17, 2026 · score 52 · 4.5 km
- July 27, 2026 · score 52 · 5.7 km
- July 27, 2026 · score 52 · 7.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 out of 100, at 79 % 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) | 52 / 100 |
| Our confidence | 79% |
| Coordinates | 39.6500, -75.0000 |
| Nearest City | Williamstown (4 km) |
| Population Exposed | 3.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-03T21:16:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Watch_noaa_urn:oid:2.49.0.1.840.0.4c169afa77b79d24f7a227d4c33cfeb8 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Watch |
| Urgency | Future |
| Certainty | Possible |
| AreaDesc | Bergen, NJ; Hudson, NJ; Bronx, NY; Kings, NY; Nassau, NY; New York, NY; Putnam, NY; Queens, NY; Richmond, NY; Rockland, NY; Westchester, NY; Essex, NJ; Passaic, NJ; Union, NJ; Orange, NY; New Castle, DE; Burlington, NJ; Camden, NJ; Gloucester, NJ; Hunterdon, NJ; Mercer, NJ; Middlesex, NJ; Monmouth, NJ; Morris, NJ; Ocean, NJ; Salem, NJ; Somerset, NJ; Sussex, NJ; Warren, NJ; Berks, PA; Bucks, PA; Carbon, PA; Chester, PA; Delaware, PA; Lehigh, PA; Monroe, PA; Montgomery, PA; Northampton, PA; Philadelphia, PA and 1 more areas |
| Headline | Severe Thunderstorm Watch issued July 3 at 5:16PM EDT until July 3 at 11:00PM EDT by NWS Upton NY |
| Expires | 2026-07-03T23:00:00-04:00 |
| SenderName | NWS Upton NY |
| HasExactCoords | false |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.4c169afa77b79d24f7a227d4c33cfeb89e57a290.001.1","noaa_urn:oid:2.49.0.1.840.0.4c169afa77b79d24f7a227d4c33cfeb89e57a290.003.1","noaa_urn:oid:2.49.0.1.840.0.10d2d21ac881d431312f6c2e671413fc9c5c67b7.001.1","noaa_urn:oid:2.49.0.1.840.0.10d2d21ac881d431312f6c2e671413fc9c5c67b7.002.1"] |
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 52/100, near Williamstown (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.