This alert expired on 2 September 2026 at 04:45 UTC. It is kept here as a record.
It is the 68th strongest of the 118 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Flash Flood Warning issued September 1 at 8:44PM EDT until September 2 at 12:45AM EDT by NWS Mount Holly NJ
An estimated 213,490 people live within 50 km of this point.
Nearby, since 12 March 2026
- March 17, 2026 · score 43 · 2.8 km
- July 4, 2026 · score 43 · 9.7 km
- March 12, 2026 · score 43 · 9.7 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 37 out of 100, at 92 % 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) | 37 / 100 |
| Our confidence | 92% |
| Coordinates | 40.3237, -76.0747 |
| Nearest City | Reading (12 km) |
| Population Exposed | 213.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-02T00:44:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.c175b0136d66bbf500e095ab82f0d44ff4c26ef1.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | New Castle, DE; Gloucester, NJ; Salem, NJ; Chester, PA; Delaware, PA; Berks, PA; Schuylkill, PA |
| Headline | Flash Flood Warning issued September 1 at 8:44PM EDT until September 2 at 12:45AM EDT by NWS Mount Holly NJ |
| Expires | 2026-09-02T00:45:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.c175b0136d66bbf500e095ab82f0d44ff4c26ef1.001.1","noaa_urn:oid:2.49.0.1.840.0.c9636d9bf9790435a1d3e4564ff15297e3ba57fb.001.1","noaa_urn:oid:2.49.0.1.840.0.5644192ce357220c3d59fea26351b0fdfbf7a6ef.001.1"] |
| Spc ReportType | wind |
| Spc Speed | UNK |
| Spc Location | 1 NNW Christiana |
| Spc County | Lancaster |
| Spc State | PA |
| Spc Comments | Reports of wires down and smoking on PA-Route 41. (CTP) |
| Iem TypeSummary | D |
| Iem City | West Bradford Twp |
| Iem County | Chester |
| Iem State | PA |
Safety Information
During flooding: never walk, swim, or drive through floodwaters. Six inches of moving water can knock you down, and one foot of water can sweep away a vehicle. Move to higher ground if waters rise. After flooding, avoid contact with floodwater which may contain sewage, chemicals, or debris. Follow local emergency service guidance.
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 Reading?
Calamity.live data shows a weather event with CalamityScore 37/100, near Reading (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.