Quarter to ping-pong ball hail confirmed across north-central Illinois – Aug 21, 2026

A line of severe thunderstorms swept through north-central Illinois on Thursday, August 21, 2026, dropping confirmed hail ranging from quarter-size to ping-pong-ball size across a broad corridor stretching from De Kalb County in the east to Carroll County near the Mississippi River. The squall line and mesoscale convective system (MCS) moved through during the mid-afternoon to early evening hours, generating multiple verified hail reports logged by the National Weather Service offices in Chicago and Davenport and the Storm Prediction Center.

Communities from Sycamore and DeKalb in the east to Mendota, Ottawa, Sterling, Dixon, and Savanna in the west are in or near the affected zone. If your home or business was exposed to yesterday’s storm, the window to document potential hail damage is now — before additional weather, foot traffic, and time obscure the evidence your insurance carrier will need to evaluate a claim.

What the National Weather Service Confirmed

Three discrete hail events were confirmed across north-central Illinois on August 21, 2026, as logged in Storm Prediction Center storm reports and attributed to NWS Chicago (WFO LOT) and NWS Davenport (WFO DVN):

• 3:09 PM CDT — De Kalb County (near Sycamore): Quarter-size hail measuring 1.00 inch in diameter was reported approximately 3 miles east of Sycamore at 42.00°N, 88.62°W. The report was submitted via mPING. This location sits approximately 37 miles west-southwest of Oak Brook.
• 6:05 PM CDT — La Salle County (near Mendota): Ping-pong-ball-size hail measuring 1.50 inches in diameter was reported approximately 3 miles north of Mendota at 41.58°N, 89.12°W. This report was confirmed via multiple photographs and represents the largest hail logged during the event. The location is approximately 63 miles west-southwest of Oak Brook.
• 6:49 PM CDT — Carroll County (near Savanna): Quarter-size hail measuring 1.00 inch in diameter was reported approximately 1 mile west-northwest of Savanna at 42.09°N, 90.16°W, confirmed via broadcast media. This location is approximately 115 miles west-northwest of Oak Brook.

The three confirmed reports span a corridor of roughly 80 miles west-to-east across north-central Illinois, reflecting the broad reach of the squall line as it tracked through the region across more than three hours. Quarter-size hail (1.00 inch) is sufficient to cause surface damage to asphalt shingles, metal roofing, gutters, vinyl siding, and other exterior surfaces under typical impact conditions. Ping-pong-ball-size hail (1.50 inches), confirmed near Mendota with photographic documentation, is considered significant and is very likely to cause functional damage to roofing systems, siding, and other exposed building components. For official storm data and current watches and warnings for your area, refer to weather.gov.

What Homeowners in Sycamore, DeKalb, Mendota, Ottawa, Sterling, Dixon, and Savanna Should Check Now

If your property is in or near one of these communities, a thorough post-storm inspection is the right move — even if you did not see or hear hail striking your home during the storm. Hail damage is frequently invisible from the ground and may not produce a visible leak for weeks or months. Here is what to look for:

Roof

• From the ground, use binoculars to scan your roofline. Look for dark circular impact marks on shingles, particularly on south- and west-facing slopes, which typically bear the greatest exposure to storm-driven hail.
• On asphalt shingles, hail impacts dislodge the protective granule surface. Check your gutters and the areas around downspout discharge for an unusual accumulation of dark granules — this is one of the earliest and most reliable ground-level indicators of shingle impact damage.
• Metal roofing, ridge caps, and flashing often display small circular dents that clearly indicate both hail contact and approximate size.
• Do not walk your own roof. If you suspect damage, have a licensed contractor conduct a proper inspection with appropriate safety equipment.

Gutters and Downspouts

• Inspect gutters for dents, dings, and accumulated shingle granules washed down from the roof surface.
• Check downspouts, gutter end caps, and splash blocks for circular impact marks consistent with the hail size reported in your area.

Siding

• Walk the full perimeter of your home. On vinyl siding, look for cracks, chips, or circular impact marks. Aluminum siding often shows denting clearly.
• Pay close attention to window trim, soffits, and fascia boards — these surfaces tend to be softer and show hail damage more visibly than the primary siding field.
• On wood siding and painted surfaces, look for chipped or missing paint and soft-impact bruising.

Windows and Skylights

• Inspect all window screens for tears or perforations from hail impact.
• Check window frames and sills for cracks or impact marks, particularly on south- and west-facing elevations.
• If your home or commercial building has skylights, inspect them carefully — skylight glazing is especially vulnerable to larger hail.

Trees, Landscaping, and HVAC

• Stripped leaves, broken branches, and shredded vegetation are useful ground-level indicators that hail was large enough and dense enough to cause surface damage to nearby structures.
• Check your air conditioning condenser unit. The thin aluminum fins on the condenser coil are a reliable hail-size indicator — denting patterns on the fins frequently correspond closely to actual hail diameter and storm density.

Interior: Water Intrusion

• After significant hail, inspect your attic space with a flashlight. Look for daylight penetrating the roof deck, moisture on insulation, or water staining on the sheathing — signs that the roof covering has been compromised.
• Check ceilings and upper-floor walls for new staining, bubbling paint, or soft spots that were not present before the storm.

Document everything you find with time-stamped photos and video before touching or cleaning anything. Systematic, thorough documentation is the foundation of a well-supported insurance claim.

If You Find Damage

Finding hail damage is not a reason to panic, but it is a reason to act promptly and deliberately. Here are the recommended next steps:

1. Document before you do anything else. Photograph all suspected damage areas thoroughly before anything is moved, cleaned, or repaired. Capture wide-angle context shots alongside close-up detail shots. A video walkthrough of the exterior adds useful supplemental documentation.
2. Notify your insurance carrier. Contact your homeowner’s or commercial property insurer to report that you suspect storm damage. Ask your agent about the claim filing deadline in your specific policy — policies vary, and some have time-sensitive notice requirements. This article is general public information and is not legal advice or insurance advice; review your specific policy language with your agent or a licensed professional.
3. Get a professional inspection from a licensed contractor. A licensed restoration contractor can conduct a thorough on-site inspection, document findings systematically, prepare a detailed repair estimate, and — if you file a claim — be present on-site when your insurance adjuster arrives. This helps ensure that all legitimate covered damage is identified and properly accounted for in the scope of work.
4. Know the difference between a restoration contractor and a public adjuster. Allied Emergency Services is a licensed roofing and restoration contractor. We document storm damage and perform covered repairs. We do not negotiate, settle, or adjust insurance claims on your behalf — those activities are performed by public adjusters or your insurer. Our role is to assess the damage accurately and do the repair work right.
5. Exercise caution with unsolicited contractors. Significant hail events attract out-of-area contractors who canvas affected neighborhoods door-to-door. Illinois law requires roofing contractors to be licensed. Always ask for a license number and verify it before signing any contract or authorization.

If your roof or exterior has been compromised and you need emergency tarping or temporary protective measures to prevent further water intrusion while your claim is being processed, a licensed restoration contractor can help you take those steps immediately. Learn more about Allied’s storm damage response services at alliedemergencyservices.com/storm-damage-restoration.

Allied Emergency Services Is Ready

Allied Emergency Services has been responding to storm damage across Illinois and the greater Midwest for 27 years. We are a licensed Illinois roofing contractor (License #104.019029) and an IICRC-certified restoration firm, headquartered in Oak Brook — well within reach of the full north-central Illinois corridor affected by yesterday’s storms, from Sycamore and DeKalb to Mendota, Ottawa, Sterling, Dixon, and Savanna. We understand the local geography, we understand insurance restoration, and we respond quickly after events like this one.

If you believe your home or commercial property sustained hail damage from the August 21st storm and you want a professional damage assessment, contact us now:

• Call 24/7: (800) 792-0212
• Text ESTIMATE to: (844) 907-2546

Our team is available around the clock following storm events. The sooner potential damage is documented and protected, the better the outcome for your property and your claim.