Severe Weather near Mercerville-Hamilton Square
Right now
The most recent data we hold from NOAA arrived 3 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 20 May 2026 at 23:30 UTC. It is kept here as a record.
It is the 5th strongest of the 221 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 20 at 6:23PM EDT until May 20 at 7:30PM EDT by NWS Mount Holly NJ
An estimated 1,865,546 people live within 50 km of this point.
Nearby, since 12 March 2026
- May 20, 2026 · score 52 · 0.2 km
- July 18, 2026 · score 52 · 2.7 km
- July 6, 2026 · score 52 · 4.2 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 85 % 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) | 52 / 100 |
| Our confidence | 85% |
| Coordinates | 40.1921, -74.4871 |
| Nearest City | Mercerville-Hamilton Square (16 km) |
| Population Exposed | 1.9M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-20T22:23:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.01121919ec9897f3f6bfd866f7ea4525 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Burlington, NJ; Mercer, NJ; Middlesex, NJ; Monmouth, NJ; Ocean, NJ; Somerset, NJ; Burlington, NJ; Mercer, NJ; Monmouth, NJ; Ocean, NJ; Bucks, PA; Burlington, NJ; Mercer, NJ; Middlesex, NJ; Monmouth, NJ; Ocean, NJ; Somerset, NJ; Bucks, PA and 5 more areas |
| Headline | Severe Thunderstorm Warning issued May 20 at 6:23PM EDT until May 20 at 7:30PM EDT by NWS Mount Holly NJ |
| Expires | 2026-05-20T19:30:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 8 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.01121919ec9897f3f6bfd866f7ea45253bf34b9c.001.1","noaa_urn:oid:2.49.0.1.840.0.070d8a46bd582ca74779483e3ccb99dd6ee6c42d.002.1","noaa_urn:oid:2.49.0.1.840.0.f34b13c9cc7b1f5b10c9438bc155dfc32dbb8e8e.002.1","noaa_urn:oid:2.49.0.1.840.0.1db25976eddd37a8008d3de1bbaa7d86a86dc174.001.1","noaa_urn:oid:2.49.0.1.840.0.8ea5f565181056ad4e412ffede8fa275295d8aae.001.1","noaa_urn:oid:2.49.0.1.840.0.2514391dfa47852a43db0d380c500bbb11b1c684.001.1","noaa_urn:oid:2.49.0.1.840.0.059cf6a47edb39c51a68aef04e66ddb907519110.001.1","noaa_urn:oid:2.49.0.1.840.0.911088494ed9b852130a5add7a3006d88fae19a1.001.1"] |
| Iem TypeSummary | D |
| Iem City | Bordentown |
| Iem County | Burlington |
| Iem State | NJ |
| Iem Wfo | PHI |
| Iem Remark | Several wires down across Bordentown and Chesterfield. Time estimated from radar. |
| MergedSources | [{"id":"iem_D_40.140_-74.710_1779314760000","source":"iem","severity":"low","severityValue":25,"timestamp":1779314760000,"latitude":40.14,"longitude":-74.71}] |
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.
Want to know when something happens near Mercerville-Hamilton Square?
Calamity.live data shows a weather event with CalamityScore 52/100, near Mercerville-Hamilton Square (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.