This alert is in force until 4 September 2026, 19:00 UTC.
It is the 13th strongest of the 26 detections recorded within 20 km of this point since 25 May 2026. The last comparable one was on 21 August 2026.
What the source measured
HEAT GOV reported: * WHAT...Heat index values up to 108 expected. * WHERE...Chesterfield, Northern Lancaster, and Southern Lancaster Counties. * WHEN...From 11 AM this morning to 8 PM EDT this evening. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.
An estimated 214,819 people live within 50 km of this point.
Nearby, since 25 May 2026
- July 10, 2026 · score 52 · 10.4 km
- June 28, 2026 · score 43 · 13.5 km
- July 12, 2026 · score 52 · 15.7 km
How we know
One source: HEAT GOV. Not yet confirmed by a second, independent source.
Our own score for this event is 37 out of 100, at 69 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 37 / 100 |
| Our confidence | 69% |
| Coordinates | 34.7358, -80.5775 |
| Nearest City | Monroe (28 km) |
| Population Exposed | 214.8K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T15:00:00.000Z |
| Source | http://www.weather.gov |
Score Breakdown
Technical Details
| Event | Heat Advisory |
| Urgency | Expected |
| Certainty | Likely |
| Onset | 2026-09-04T11:00:00-04:00 |
| Expires | 2026-09-04T15:00:00-04:00 |
| AreaDesc | Chesterfield; Northern Lancaster; Southern Lancaster |
| SenderName | NWS Columbia SC |
| ZonesUsedForCentroid | 3 |
| ZoneCount | 3 |
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 Monroe?
Calamity.live data shows a weather event with CalamityScore 37/100, near Monroe (United States), based on data from heat_gov. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.