This alert expired on 26 June 2026 at 22:15 UTC. It is kept here as a record.
It is the 6th strongest of the 66 detections recorded within 20 km of this point since 17 March 2026. The last comparable one was on 23 June 2026. 14 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 26 at 5:09PM EDT until June 26 at 6:15PM EDT by NWS Boston/Norton MA
An estimated 493,942 people live within 50 km of this point.
Nearby, since 17 March 2026
- June 26, 2026 · score 48 · 8.4 km
- June 18, 2026 · score 43 · 15.8 km
- July 16, 2026 · score 43 · 16.9 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 37 out of 100, at 78 % 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 | 78% |
| Coordinates | 42.8713, -71.9055 |
| Nearest City | Keene (31 km) |
| Population Exposed | 493.9K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-26T21:09:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.afb37be3ef1d0b188b88e62feb3499e8 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Hampden, MA; Hampshire, MA; Worcester, MA; Merrimack, NH; Rockingham, NH; Strafford, NH; Merrimack, NH; Sullivan, NH |
| Headline | Severe Thunderstorm Warning issued June 26 at 5:09PM EDT until June 26 at 6:15PM EDT by NWS Boston/Norton MA |
| Expires | 2026-06-26T18:15:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.afb37be3ef1d0b188b88e62feb3499e845d63cd1.001.1","noaa_urn:oid:2.49.0.1.840.0.47a2699ae41227401718442843377c815803d408.001.1","noaa_urn:oid:2.49.0.1.840.0.4ab4f68d60ed5af37303788d89b67e94d7f447d6.001.1"] |
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.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 37/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.