The estimated-size surface reached 2.75" aloft; NEXRAD logged no point detections over Downers Grove that day. At 2.75" — baseball — this is a severe hail signal associated with roof damage. Open it on the live map to see the swath over the streets.
A tornado was also reported to the National Weather Service during this storm. The ground reports below show where it was filed.
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Convective day · Jul 27, 2026 · noon–noon UTC
Severity
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
Largest radar-indicated size — a signal of damage potential, not confirmation.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
Evidence / storm surfaces
The maps here read the same storm from two angles — point detections from NEXRAD, and modeled hail size aloft. Where the two disagree is informative: it marks where estimated size outran the signatures, or trailed them.
Estimated size field The modeled maximum hail size across the swath, derived from radar aloft — the largest stone the storm could have supported, which is not necessarily what reached the ground.
Only the radar-estimated size surface resolved for Jul 27, 2026 — this storm produced no NEXRAD point detections over Downers Grove, so there is one map to show, not two.
The storm in context
This was Downers Grove's 6th recorded hail day, arriving 44 days after the Jun 13, 2026 storm. By severity it ranks 1st of the 7 storms we have logged here. Radar put the day's largest stone over Downers Grove at 2.75" — radar-estimated size aloft.
The Jul 27, 2026 convective day was bigger than Downers Grove: the same system put hail over 803 other tracked cities, 130 of them in Illinois. Nearest: Lisle (5 miles west, up to 2.75"); Wheaton (5 miles west, up to 2.75"); Western Springs (5 miles east, up to 2.25").
These maps are stills. In the app this date is one of 7 Downers Grove storm dates on a live map — both surfaces, the reports, and a replay — and the same map is where you draw the swath. This page rebuilds nightly.
Ground reports
These are storm reports filed with the National Weather Service and released through the NOAA Storm Prediction Center — public-domain observations from spotters, the public, and NWS surveys. We quote each one exactly as filed.
“An NWS damage survey confirmed an EF-0 tornado with peak winds of 85 mph... path length of 2.1 miles... and maximum width of 100 yards impacted Downers Grove. (LOT)”
— NOAA / SPC storm report
“Relayed via mping. Time estimated by radar. (LOT)”
— NOAA / SPC storm report
“Photo shared to social media shows half dollar size hail near 67th Street and Clarendon Hills Road. Time estimated by radar. (LOT)”
— NOAA / SPC storm report
“Measured hailstone of 2 inches in diameter. Time estimated by radar. (LOT)”
— NOAA / SPC storm report
“Photo shared on social media of golf ball size hail. (LOT)”
— NOAA / SPC storm report
“Public report of ping pong ball size hail at Oakbrook Terrace. Time estimated by radar. (LOT)”
— NOAA / SPC storm report
“Public report of golf ball size hail in Oak Brook. Time estimated by radar. (LOT)”
— NOAA / SPC storm report
“Report from mPING: Hen Egg (2.00 in.). (LOT)”
— NOAA / SPC storm report
“Trained spotter reported 2 inch diameter hail in Clarendon Hills. Time estimated by radar. (LOT)”
— NOAA / SPC storm report
“Photo shared on social media showing a hailstone roughly two inches in diameter. (LOT)”
— NOAA / SPC storm report
“(LOT)”
— NOAA / SPC storm report
“Relayed via mping. (LOT)”
— NOAA / SPC storm report
“Relayed via mping. (LOT)”
— NOAA / SPC storm report
“Relayed via mping. Time estimated by radar. (LOT)”
— NOAA / SPC storm report
“(LOT)”
— NOAA / SPC storm report
Storm forensics
Read from the arrival times and locations of the NOAA ground reports, not a radar-measured storm track.
The storm tracked southeast at roughly 10 mph, based on the timing of ground reports.
Hail was reported over 39 minutes, from to .
Reports came from Darien, Willowbrook, Oakbrook Terrace, Oak Brook, Clarendon Hills, and Westmont — beyond Downers Grove itself.
Severe hail signal
Two-inch-plus hail is capable of puncturing shingles, breaking skylights or windows, and heavily denting soft materials. The strongest radar bands warrant prompt inspection, but neither the signal nor the footprint confirms damage at a specific address.
Radar reading · not confirmed damage
Roofing exposure
Potential roof exposure
$858M
Potential roof exposure — 71,523 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
Close just 0.5% of the 71,523 homes in this footprint at the average $15,000 roof job. Illustrative math, not a projection — your results depend on your outreach and how the market responds.
Claim window
July 2028
Claims from this storm can typically be filed until around July 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Names and phones for every home in the footprint: at most $15,020 on top of the $150 plan.
Downers Grove hail history
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NEXRAD surface Set your territory and alerts today. When hail hits, use Overview to choose your streets and get moving.
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Web trial: 7 days free. Card required. $150/month after the trial unless cancelled.