This alert expired on 17 May 2026 at 01:45 UTC. It is kept here as a record.
It is the 40th strongest of the 82 detections recorded within 20 km of this point since 15 March 2026. The last comparable one was on 28 April 2026.
What the source measured
NOAA reported: Flood Warning issued May 15 at 8:35AM CDT until May 19 at 7:00PM CDT by NWS St Louis MO
An estimated 44,089 people live within 50 km of this point.
Nearby, since 15 March 2026
- May 18, 2026 · score 34 · 0.0 km
- May 17, 2026 · score 34 · 0.0 km
- May 16, 2026 · score 43 · 5.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 34 out of 100, at 79 % 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) | 34 / 100 |
| Our confidence | 79% |
| Coordinates | 38.5650, -89.3767 |
| Nearest City | O'Fallon (46 km) |
| Population Exposed | 44.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-15T13:35:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.580cc3dd1bc88e306cfda11b71a2e44cb0a13c84.001.1 |
Score Breakdown
Technical Details
| Event | Flood Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Clinton, IL |
| Headline | Flood Warning issued May 15 at 8:35AM CDT until May 19 at 7:00PM CDT by NWS St Louis MO |
| Expires | 2026-05-16T20:45:00-05:00 |
| SenderName | NWS St Louis MO |
| HasExactCoords | true |
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 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.
Calamity.live data shows a weather event with CalamityScore 34/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.