This alert expired on 4 July 2026 at 01:45 UTC. It is kept here as a record.
It is the 7th strongest of the 28 detections recorded within 20 km of this point since 2 April 2026. The last comparable one was on 3 July 2026. 11 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 3 at 8:24PM CDT until July 3 at 8:45PM CDT by NWS Chicago IL
An estimated 946,381 people live within 50 km of this point.
Nearby, since 2 April 2026
- July 4, 2026 · score 48 · 12.1 km
- July 3, 2026 · score 46 · 15.1 km
- June 24, 2026 · score 52 · 17.0 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 48 out of 100, at 90 % 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) | 48 / 100 |
| Our confidence | 90% |
| Coordinates | 42.0199, -88.8045 |
| Nearest City | Sycamore (10 km) |
| Population Exposed | 946.4K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-04T01:24:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.0780746ebecaf353544df11c50bfe4c1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Lee, IL; Ogle, IL; De Kalb, IL; Kane, IL |
| Headline | Severe Thunderstorm Warning issued July 3 at 8:24PM CDT until July 3 at 8:45PM CDT by NWS Chicago IL |
| Expires | 2026-07-03T20:45:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.0780746ebecaf353544df11c50bfe4c1bb1bd003.001.1","noaa_urn:oid:2.49.0.1.840.0.347e1d100ea240db94b0bfc0574ae6c4e2d0c8cb.001.1"] |
| Iem TypeSummary | E |
| Iem City | 1 N Lisle |
| Iem County | DuPage |
| Iem State | IL |
| Iem Wfo | LOT |
| Iem Remark | Water is covering Route 53 at Ironwood Drive. Minor wetland flooding also noted along the DuPage River nearby, as well. |
| MergedSources | [{"id":"iem_G_41.890_-89.080_1783122900000","source":"iem","severity":"low","severityValue":25,"timestamp":1783122900000,"latitude":41.89,"longitude":-89.08},{"id":"iem_E_41.820_-88.070_1783108800000","source":"iem","severity":"low","severityValue":25,"timestamp":1783108800000,"latitude":41.82,"longitude":-88.07}] |
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 48/100, near Sycamore (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.