Right now
The most recent data we hold from NOAA arrived 4 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 July 2026 at 13:00 UTC. It is kept here as a record.
It is the 2nd strongest of the 7 detections recorded within 20 km of this point since 15 March 2026. The last comparable one was on 9 July 2026. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 20 at 7:35AM CDT until July 20 at 8:00AM CDT by NWS Des Moines IA
An estimated 69,603 people live within 50 km of this point.
Nearby, since 15 March 2026
- July 9, 2026 · score 34 · 22.0 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 39 out of 100, at 81 % 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) | 39 / 100 |
| Our confidence | 81% |
| Coordinates | 43.3560, -93.1720 |
| Nearest City | Mason City (23 km) |
| Population Exposed | 69.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-20T12:35:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.ce964a8a51be380825b0376935ea1f837a6a3045.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Worth, IA |
| Headline | Severe Thunderstorm Warning issued July 20 at 7:35AM CDT until July 20 at 8:00AM CDT by NWS Des Moines IA |
| Expires | 2026-07-20T08:00:00-05:00 |
| SenderName | NWS Des Moines IA |
| HasExactCoords | true |
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 Mason City?
Calamity.live data shows a weather event with CalamityScore 39/100, near Mason City (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.