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 30 June 2026 at 12:30 UTC. It is kept here as a record.
No stronger detection stands among the 35 recorded within 20 km of this point since 16 March 2026 — 18 others scored the same. Another comparable one was recorded here earlier the same day. 23 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued June 30 at 4:37AM CDT until June 30 at 7:30AM CDT by NWS Sioux Falls SD
An estimated 82,821 people live within 50 km of this point.
How we know
Confirmed by 10 independent sources, including NOAA.
Our own score for this event is 45 out of 100, at 91 % 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 | High |
| Calamity Score (ours) | 45 / 100 |
| Our confidence | 91% |
| Coordinates | 42.4911, -96.4222 |
| Nearest City | Sioux City (2 km) |
| Population Exposed | 82.8K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-06-30T09:37:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.45a48571b80d9e142d95ec4bd56f38309e943c3f.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Woodbury, IA; Dakota, NE |
| Headline | Flash Flood Warning issued June 30 at 4:37AM CDT until June 30 at 7:30AM CDT by NWS Sioux Falls SD |
| Expires | 2026-06-30T07:30:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | 4 ESE Sioux City |
| Spc County | Woodbury |
| Spc State | IA |
| Spc Comments | (FSD) |
| Iem TypeSummary | H |
| Iem Magnitude | 1 |
| Iem Unit | Inch |
| Iem City | 2 SE Sioux City |
| Iem County | Woodbury |
| Iem State | IA |
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 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 Sioux City?
Calamity.live data shows a weather event with CalamityScore 45/100, near Sioux City (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.