Grant County was hit as recently as 2026-07-02, 29 days ago. Grant County is hit in most years. The largest stone on record here is 2.75 inches, a baseball and 2.8 times the National Weather Service's 1 inch severe criterion, reported on 2025-04-17 near Platteville.
Colored swath = NOAA MRMS radar-estimated hail size; dots = NOAA SPC reports in Wisconsin. Radar-indicated, not a guarantee of damage.
The last hail here fell on 2026-07-02, around Glen Haven. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Grant County addresses inside a hail swath above your size threshold into a door-knock list you can export, scoped to your approved markets.
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See call-center options ->NOAA's Storm Prediction Center has logged 28 separate hail days here since 2010 -- 1.6 a year over 17 years of record. Those days carry 64 separate reports between them, two or three on a typical one. 3 of those 17 years produced none at all. The busiest single year was 2026, with 4 hail days. The last five years track the long-run rate, with 9 days since 2022.
5 of the 28 days reached 2 inches or more -- 18%, or about one hail day in 6, the last on 2026-07-02. They land in the same month as everything else, April. 10 of the 28 days reached golf-ball size, 1.75 inches or bigger.
Across the whole of Wisconsin, see the Wisconsin hail map and history.
Reports cluster nearest Platteville -- 6 of the county's 28 hail days -- then Fennimore (4), Glen Haven (3), Patch Grove (3) and Lancaster (3). Beyond those, NOAA names Montfort, Tennyson, Dickeyville, Hazel Green, Potosi and Woodman on more than one hail day apiece.
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| Platteville | 5 | 2.00″ |
| 1 NW Platteville | 2 | 2.00″ |
| 3 E Potosi | 2 | 1.75″ |
| Dickeyville | 2 | 1.75″ |
| 4 W Lancaster | 2 | 1.00″ |
The season runs April through August: 23 of the 28 hail days on record fall in those 5 months (82%). April is the single busiest month, with 7 of them (25%). That peak opens the window: the season starts at its worst and eases off from there. Hail has also been reported in March and September, outside that window. Reports span 7 of the 12 calendar months; the other 5 have never produced one.
| Month | Hail days |
|---|---|
| March | 2 |
| April | 7 |
| May | 5 |
| June | 4 |
| July | 4 |
| August | 3 |
| September | 3 |
That day put 2 reports on the map, the biggest 2 inches near Glen Haven. 4 hail days have already been reported this year.
| Date | Max hail | Reports |
|---|---|---|
| 2026-07-02 | 2.00″ | 2 |
| 2026-06-24 | 1.00″ | 1 |
| 2026-04-14 | 2.00″ | 3 |
| 2026-03-10 | 1.00″ | 1 |
| 2025-09-22 | 2.00″ | 2 |
| 2025-08-16 | 1.00″ | 1 |
| 2025-04-17 | 2.75″ | 12 |
| 2024-05-21 | 1.75″ | 5 |
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 2.75 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: Iowa County (18 hail days), Richland County (15), Green County (18), Dubuque County, Iowa (27) and Clayton County, Iowa (22). Grant County takes more hail than any of them.
Iowa County · Richland County · Green County · Dubuque County, Iowa · Clayton County, Iowa
Back to the Wisconsin hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Grant County, Wisconsin only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.