This alert expired on 3 July 2026 at 18:30 UTC. It is kept here as a record.
It is the 16th strongest of the 55 detections recorded within 20 km of this point since 15 April 2026. Another comparable one was recorded here earlier the same day. 7 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 3 at 12:42PM CDT until July 3 at 1:30PM CDT by NWS Milwaukee/Sullivan WI
An estimated 1,445,630 people live within 50 km of this point.
Nearby, since 15 April 2026
- July 3, 2026 · score 46 · 8.0 km
- July 4, 2026 · score 48 · 14.2 km
- July 4, 2026 · score 48 · 15.1 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 46 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) | 46 / 100 |
| Our confidence | 84% |
| Coordinates | 41.9488, -88.6481 |
| Nearest City | Sycamore (6 km) |
| Population Exposed | 1.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-03T17:42:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.75ae9ab0a0ae9bf6e4b0ed4e220ad2a5 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Kenosha, WI; Racine, WI; Cook, IL; DuPage, IL; Kane, IL; Bureau, IL; Putnam, IL and 1 more areas |
| Headline | Severe Thunderstorm Warning issued July 3 at 12:42PM CDT until July 3 at 1:30PM CDT by NWS Milwaukee/Sullivan WI |
| Expires | 2026-07-03T13:30:00-05:00 |
| SenderName | NWS Milwaukee/Sullivan WI |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.75ae9ab0a0ae9bf6e4b0ed4e220ad2a599658f08.001.1","noaa_urn:oid:2.49.0.1.840.0.4f398e61e3e8ca1acfd10f535a014414c1cf7881.001.1","noaa_urn:oid:2.49.0.1.840.0.b0720f5ee59df288ac9d0930ded061aee4fd9d53.001.1","noaa_urn:oid:2.49.0.1.840.0.289278955662636ea96ebbb90a6fff08dbd5ed07.001.1"] |
| Iem TypeSummary | D |
| Iem City | Rockton |
| Iem County | Winnebago |
| Iem State | IL |
| Iem Wfo | LOT |
| Iem Remark | Multiple photos and reports of downed trees and power lines in and around Rockton including near MacTown Forest Preserve and Settlers Park. Time estimated by radar. |
| MergedSources | [{"id":"iem_D_42.450_-89.070_1783096980000","source":"iem","severity":"low","severityValue":25,"timestamp":1783096980000,"latitude":42.45,"longitude":-89.07}] |
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.
Want to know when something happens near Sycamore?
Calamity.live data shows a weather event with CalamityScore 46/100, near Sycamore (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.