This alert expired on 18 May 2026 at 15:30 UTC. It is kept here as a record.
It is the 192nd strongest of the 385 detections recorded within 20 km of this point since 15 March 2026. The last comparable one was on 5 May 2026. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 18 at 9:49AM CDT until May 18 at 10:30AM CDT by NWS Lincoln IL
An estimated 112,563 people live within 50 km of this point.
Nearby, since 15 March 2026
- June 18, 2026 · score 49 · 6.6 km
- March 15, 2026 · score 67 · 11.9 km
- May 18, 2026 · score 43 · 13.0 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 43 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 | Medium |
| Calamity Score (ours) | 43 / 100 |
| Our confidence | 91% |
| Coordinates | 39.6679, -88.5923 |
| Nearest City | Mattoon (28 km) |
| Population Exposed | 112.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T14:49:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.3f3aeba2924419b7274d412a52664a0c |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Christian, IL; Macon, IL; Shelby, IL; De Witt, IL; Macon, IL; Piatt, IL; Coles, IL; Douglas, IL; Edgar, IL |
| Headline | Severe Thunderstorm Warning issued May 18 at 9:49AM CDT until May 18 at 10:30AM CDT by NWS Lincoln IL |
| Expires | 2026-05-18T10:30:00-05:00 |
| SenderName | NWS Lincoln IL |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.3f3aeba2924419b7274d412a52664a0cb825b1e0.001.1","noaa_urn:oid:2.49.0.1.840.0.60a050537dae70e5ae1a747e2c84db97dfe78cd5.001.1","noaa_urn:oid:2.49.0.1.840.0.1bd7bfc15593787cf89fec07958096c6d0e2d658.001.1"] |
| Iem TypeSummary | D |
| Iem City | 1 WNW Assumption |
| Iem County | Christian |
| Iem State | IL |
| Iem Wfo | ILX |
| Iem Remark | Large tree limbs down. |
| MergedSources | [{"id":"iem_G_39.530_-89.330_1779115200000","source":"iem","severity":"low","severityValue":25,"timestamp":1779115200000,"latitude":39.53,"longitude":-89.33},{"id":"iem_D_39.520_-89.060_1779112920000","source":"iem","severity":"low","severityValue":25,"timestamp":1779112920000,"latitude":39.52,"longitude":-89.06}] |
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 Mattoon?
Calamity.live data shows a weather event with CalamityScore 43/100, near Mattoon (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.