This alert expired on 18 June 2026 at 22:15 UTC. It is kept here as a record.
No stronger detection stands among the 65 recorded within 20 km of this point since 17 March 2026 — one other scored the same. Another comparable one was recorded here earlier the same day. 4 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued June 18 at 5:30PM EDT until June 18 at 6:15PM EDT by NWS Boston/Norton MA
An estimated 760,972 people live within 50 km of this point.
Nearby, since 17 March 2026
- July 28, 2026 · score 52 · 9.6 km
- June 7, 2026 · score 48 · 10.1 km
- May 19, 2026 · score 48 · 12.8 km
How we know
Confirmed by 14 independent sources, including NOAA.
Our own score for this event is 72 out of 100, at 89 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | critical |
| Calamity Score (ours) | 72 / 100 |
| Our confidence | 89% |
| Coordinates | 42.2880, -71.9810 |
| Nearest City | Holden (12 km) |
| Population Exposed | 761.0K within 50 km |
| Impact Tier | catastrophic |
| Timestamp | 2026-06-18T21:30:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Tornado Warning_noaa_urn:oid:2.49.0.1.840.0.bdf543025a772af1074b311613195a73 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Hampden, MA; Hampshire, MA; Worcester, MA; Middlesex, MA; Worcester, MA |
| Headline | Tornado Warning issued June 18 at 5:30PM EDT until June 18 at 6:15PM EDT by NWS Boston/Norton MA |
| Expires | 2026-06-18T18:15:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.bdf543025a772af1074b311613195a73deccbdd6.001.1","noaa_urn:oid:2.49.0.1.840.0.cb44f32923665e2bf19e357d471e9ea5c1455e77.001.1"] |
| Iem TypeSummary | D |
| Iem City | Harrisville |
| Iem County | Cheshire |
| Iem State | NH |
| Iem Wfo | GYX |
| Iem Remark | Large tree down on Cheshire Rd. Time estimated from radar. |
| MergedSources | [{"id":"iem_D_42.690_-72.040_1781814300000","source":"iem","severity":"low","severityValue":25,"timestamp":1781814300000,"latitude":42.69,"longitude":-72.04},{"id":"iem_D_42.790_-71.950_1781814180000","source":"iem","severity":"low","severityValue":25,"timestamp":1781814180000,"latitude":42.79,"longitude":-71.95},{"id":"iem_D_42.650_-72.610_1781812140000","source":"iem","severity":"low","severityValue":25,"timestamp":1781812140000,"latitude":42.65,"longitude":-72.61},{"id":"iem_D_42.690_-72.330_1781813400000","source":"iem","severity":"low","severityValue":25,"timestamp":1781813400000,"latitude":42.69,"longitude":-72.33},{"id":"iem_D_42.410_-71.960_1781816760000","source":"iem","severity":"low","severityValue":25,"timestamp":1781816760000,"latitude":42.41,"longitude":-71.96},{"id":"iem_D_42.890_-72.270_1781811780000","source":"iem","severity":"low","severityValue":25,"timestamp":1781811780000,"latitude":42.89,"longitude":-72.27},{"id":"iem_D_42.600_-72.590_1781812200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781812200000,"latitude":42.6,"longitude":-72.59},{"id":"iem_D_42.900_-71.780_1781814180000","source":"iem","severity":"low","severityValue":25,"timestamp":1781814180000,"latitude":42.9,"longitude":-71.78},{"id":"iem_D_42.600_-72.600_1781812200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781812200000,"latitude":42.6,"longitude":-72.6},{"id":"iem_D_42.560_-72.760_1781812200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781812200000,"latitude":42.56,"longitude":-72.76},{"id":"iem_D_42.700_-71.820_1781815200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781815200000,"latitude":42.7,"longitude":-71.82},{"id":"iem_D_42.580_-72.440_1781814000000","source":"iem","severity":"low","severityValue":25,"timestamp":1781814000000,"latitude":42.58,"longitude":-72.44},{"id":"iem_D_42.940_-72.090_1781811900000","source":"iem","severity":"low","severityValue":25,"timestamp":1781811900000,"latitude":42.94,"longitude":-72.09}] |
Safety Information
If a tornado warning is issued: go to a basement or an interior room on the lowest floor, away from windows. A vehicle and a mobile home are not shelter. Cover your head and neck. Wait for the official all-clear before going outside, and watch for downed power lines and gas leaks afterwards.
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 Holden?
Calamity.live data shows a weather event with CalamityScore 72/100, near Holden (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.