The most recent reported hail day was 2026-04-17, 105 days ago. Winnebago County is hit in most years, and usually several times over. The largest stone on record here is 3 inches, a teacup and 3 times the National Weather Service's 1 inch severe criterion, reported on 2020-04-07 near Winnebago.
Colored swath = NOAA MRMS radar-estimated hail size; dots = NOAA SPC reports in Illinois. Radar-indicated, not a guarantee of damage.
The last hail here fell on 2026-04-17, around Lake Summerset. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Winnebago County addresses inside a hail swath above your size threshold into a door-knock list you can export, scoped to your approved markets.
Get free access Check an addressOur US-based call center calls the homeowners in this storm and books roof inspections straight onto your calendar. You work the storm; we fill the schedule. We dial -- you do not have to knock a single door.
See call-center options ->NOAA's Storm Prediction Center has logged 41 separate hail days here since 2010 -- 2.4 a year over 17 years of record. Those days carry 122 separate reports between them, two or three on a typical one. 2 of those 17 years produced none at all. The busiest single year was 2011, with 5 hail days. The last five years track the long-run rate, with 13 days since 2022.
6 of the 41 days reached 2 inches or more -- 15%, or about one hail day in 7, the last on 2026-04-17. Those big days do not follow the county's usual calendar: most of them fall in May, not April. 13 of the 41 days reached golf-ball size, 1.75 inches or bigger.
Across the whole of Illinois, see the Illinois hail map and history.
Reports cluster nearest Rockford -- 14 of the county's 41 hail days -- then Loves Park (9), Pecatonica (9), Cherry Valley (8) and Winnebago (7). Beyond those, NOAA names Rockford Airport, Machesney Park, South Beloit, Durand, Roscoe, Rockton and Lake Summerset on more than one hail day apiece.
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| Rockford | 10 | 2.50″ |
| Winnebago | 6 | 3.00″ |
| Loves Park | 5 | 2.00″ |
| Rockford Airport | 5 | 2.00″ |
| Pecatonica | 5 | 1.75″ |
The season runs April through August: 34 of the 41 hail days on record fall in those 5 months (83%). April is the single busiest month, with 11 of them (27%). That peak opens the window: the season starts at its worst and eases off from there. Hail has also been reported in February, March, September and November, outside that window. January, October and December are the only months that have never produced a reported hail day.
| Month | Hail days |
|---|---|
| February | 1 |
| March | 3 |
| April | 11 |
| May | 11 |
| June | 4 |
| July | 4 |
| August | 4 |
| September | 1 |
| November | 2 |
That day put 10 reports on the map, the biggest 2.25 inches near Lake Summerset. 3 hail days have already been reported this year.
| Date | Max hail | Reports |
|---|---|---|
| 2026-04-17 | 2.25″ | 10 |
| 2026-04-15 | 1.00″ | 2 |
| 2026-04-14 | 1.00″ | 1 |
| 2025-07-10 | 1.50″ | 6 |
| 2025-05-16 | 1.00″ | 2 |
| 2024-05-04 | 1.00″ | 1 |
| 2024-02-27 | 1.50″ | 1 |
| 2023-08-16 | 1.00″ | 1 |
The colored swath is NOAA's MRMS radar estimate of the largest hail per ~1 km cell; the dots are SPC ground reports. Yellow is about an inch, red 1.5 to 2″, purple 2″ and up (hail size vs roof damage). On this county's worst day the reports reached 3 inches, which is the purple band. Look up a street address with the hail history by address tool.
The nearest counties with a page of their own, over the state line included: Boone County (20 hail days), Ogle County (25), Stephenson County (21) and Rock County, Wisconsin (32). Winnebago County takes more hail than any of them.
Boone County · Ogle County · Stephenson County · Rock County, Wisconsin
Back to the Illinois hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Winnebago County, Illinois only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.