Severe weather near Fairview Heights
This alert expired on 18 May 2026 at 23:00 UTC. It is kept here as a record.
It is the 3rd strongest of the 46 detections recorded within 20 km of this point since 15 March 2026. 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: Flash Flood Warning issued May 18 at 3:56PM CDT until May 18 at 6:00PM CDT by NWS Lincoln IL
An estimated 1,006,174 people live within 50 km of this point.
Nearby, since 15 March 2026
- July 11, 2026 · score 48 · 5.6 km
- May 19, 2026 · score 52 · 11.1 km
- May 18, 2026 · score 52 · 11.1 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 84 % 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) | 52 / 100 |
| Our confidence | 84% |
| Coordinates | 38.5611, -89.9725 |
| Nearest City | Fairview Heights (4 km) |
| Population Exposed | 1.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T20:56:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.c80b4e429257b3792218c6e020108ce1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Clay, IL; Clay, IL; Effingham, IL; Jasper, IL; Bond, IL; Clinton, IL; Fayette, IL; Marion, IL; Washington, IL and 3 more areas |
| Headline | Flash Flood Warning issued May 18 at 3:56PM CDT until May 18 at 6:00PM CDT by NWS Lincoln IL |
| Expires | 2026-05-18T18:00:00-05:00 |
| SenderName | NWS Lincoln IL |
| HasExactCoords | true |
| MergedCount | 6 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.c80b4e429257b3792218c6e020108ce1342b51d9.001.1","noaa_urn:oid:2.49.0.1.840.0.e3af18ef65f13c8f2f4cf32e0021e124f57ea286.001.1","noaa_urn:oid:2.49.0.1.840.0.dbabff3a536120a3ca09dab0ff473b6cc62da205.002.1","noaa_urn:oid:2.49.0.1.840.0.f51d25858704af1517e0bba1e5bf5148f039ac5f.001.1","noaa_urn:oid:2.49.0.1.840.0.981763280e670dafdad02306926ecdd4a788a568.001.1","noaa_urn:oid:2.49.0.1.840.0.7a20f69a9e55d71d7a393b43d10d36416df44d41.001.1"] |
| Iem TypeSummary | H |
| Iem Magnitude | 0.7 |
| Iem Unit | Inch |
| Iem City | 1 NNE Oakville |
| Iem County | St. Louis |
| Iem State | MO |
| Iem Wfo | LSX |
| Iem Remark | NWS employee reported dime-size hail. |
| MergedSources | [{"id":"iem_H_38.460_-90.310_1779120300000","source":"iem","severity":"low","severityValue":25,"timestamp":1779120300000,"latitude":38.46,"longitude":-90.31}] |
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 52/100, near Fairview Heights (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.