This alert expired on 10 August 2026 at 05:45 UTC. It is kept here as a record.
It is the 20th strongest of the 130 detections recorded within 20 km of this point since 10 March 2026. The last comparable one was on 9 August 2026. 20 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 9 at 11:35PM CDT until August 10 at 12:45AM CDT by NWS Chicago IL
An estimated 1,930,079 people live within 50 km of this point.
Nearby, since 10 March 2026
- August 10, 2026 · score 52 · 3.3 km
- July 27, 2026 · score 76 · 7.0 km
- March 11, 2026 · score 58 · 7.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 out of 100, at 81 % 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 | 81% |
| Coordinates | 41.5875, -88.3635 |
| Nearest City | Yorkville (9 km) |
| Population Exposed | 1.9M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-10T04:35:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Grundy, IL; La Salle, IL; Livingston, IL; Cook, IL; Lake, IL |
| Headline | Severe Thunderstorm Warning issued August 9 at 11:35PM CDT until August 10 at 12:45AM CDT by NWS Chicago IL |
| Expires | 2026-08-10T00:45:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.9d75e6c62642d3c97c3b521da175507d38352891.001.1","noaa_urn:oid:2.49.0.1.840.0.24c32a9bf9ec81250d2ede64381dba1612f6d970.001.1"] |
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 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 Yorkville (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 191 scientific monitoring sources.