Rock County, Wisconsin: hail history 2014–2026
Rock County ranks #8 of 50 Wisconsin counties for hail: 101.9 reports per 1,000 square miles, 74 reports in all. Hail reached 1 inch on 25 days and 1.75 inches on 4. Record: 2.75 inches (a baseball), April 18, 2025 near Evansville.
- 74reports
- 25days, 1 in+
- 4days, 1.75 in+
- 2.75 inlargest stone
Hail since my roof went on: Rock County
Year by year
| Year | Reports | Days 1 in+ | Days 1.75 in+ | Largest |
|---|---|---|---|---|
| 2014 | 5 | 3 | 1 | 1.75 in |
| 2015 | 2 | 1 | 0 | 1 in |
| 2016 | 4 | 2 | 0 | 1 in |
| 2017 | 3 | 2 | 0 | 1 in |
| 2018 | 3 | 1 | 0 | 1.5 in |
| 2019 | 2 | 2 | 0 | 1 in |
| 2020 | 2 | 1 | 0 | 1 in |
| 2021 | 4 | 2 | 0 | 1 in |
| 2022 | 9 | 2 | 1 | 2 in |
| 2023 | 2 | 1 | 0 | 1.25 in |
| 2024 | 10 | 2 | 0 | 1.5 in |
| 2025 | 18 | 2 | 1 | 2.75 in |
| 2026 (Jan–Jun) | 10 | 4 | 1 | 2 in |
2025 was the busiest year (18 reports) and 2015 the quietest (2). Rock County averaged 8 reports a year from 2020 to 2025, 137% above the 3 of 2014 to 2019. 2026 stands at 10 through June, already past the full-year average of 5. Days with 1-inch stones average 1.8 per full year.
Rock County: reports by month
| Jan | 0 |
|---|---|
| Feb | 1 |
| Mar | 5 |
| Apr | 23 |
| May | 10 |
| Jun | 7 |
| Jul | 10 |
| Aug | 12 |
| Sep | 5 |
| Oct | 1 |
| Nov | 0 |
| Dec | 0 |
April dominates the calendar: 23 of 74 reports, 31%. April to June alone bring 54%. 7 of 74 reports fell outside April to September.
Largest stone: 2.75 inches
Reported hail locations, Rock County
- 431 to 1.74 in
- 141.75 to 2.74 in, golf ball to tennis ball
- 32.75 in and up, baseball
Largest plotted stone: 2.75 in. Bigger dots are bigger stones.
60 reports of 1 inch or larger have coordinates. Each dot is a reported location, not a storm path.
Sources: NOAA, Census county outlineRock County’s ten biggest hail days
| Date | Size | Reports | Place |
|---|---|---|---|
| April 18, 2025 | 2.75 in, a baseball | 11 | Evansville |
| July 23, 2022 | 2 in, a hen egg | 5 | Mallwood |
| April 17, 2026 | 2 in, a hen egg | 4 | Beloit |
| May 12, 2014 | 1.75 in, a golf ball | 2 | Beloit |
| August 16, 2025 | 1.5 in, a ping-pong ball | 7 | Downtown Janesville |
| April 2, 2026 | 1.5 in, a ping-pong ball | 4 | Downtown Janesville |
| May 2, 2018 | 1.5 in, a ping-pong ball | 3 | Downtown Janesville |
| March 4, 2024 | 1.5 in, a ping-pong ball | 3 | Avon |
| June 25, 2024 | 1.25 in, a half dollar | 5 | Downtown Janesville |
| April 4, 2023 | 1.25 in, a half dollar | 1 | Cooksville |
“Eventually these storms transitioned to a squall line which had a number of tornadoes associated with it, as it tracked through southeast Wisconsin. Many large hail reports and a small number of downburst damaging wind reports were also received.”
NWS report, April 17, 2026
“Storm spotters and law enforcement reported hail ranging from 1 to 1.75 inches in diameter.”
NWS report, May 12, 2014
Tornadoes and wind in Rock County
15 tornadoes on record in Rock County; the strongest listed is EF2, 13.71 miles long, near Magnolia. Top gust: 85 mph near Newark.
| Date | Rating | Path length | Width | Near |
|---|---|---|---|---|
| February 8, 2024 | EF2 | 13.71 mi | 750 yd | Magnolia · 0 deaths, 1 injured |
| June 22, 2024 | EF2 | 6.03 mi | 700 yd | Afton |
| April 17, 2026 | EF1 | 3.3 mi | 75 yd | Johnstown Center |
| April 17, 2026 | EF1 | 2.06 mi | 100 yd | Emerald Grove |
| April 17, 2026 | EF1 | 1.89 mi | 75 yd | Tiffany |
| July 18, 2015 | EF1 | 1.8 mi | 50 yd | Johnstown |
| May 26, 2024 | EF0 | 11.83 mi | 50 yd | Leyden |
| May 26, 2024 | EF0 | 10.89 mi | 50 yd | Emerald Grove |
| Date | Gust | Near |
|---|---|---|
| June 10, 2026 | 85 mph | Newark |
| September 17, 2015 | 81 mph | Downtown Janesville |
| March 6, 2017 | 81 mph | Leyden |
| May 17, 2017 | 81 mph | Downtown Janesville |
| May 17, 2017 | 81 mph | Fairfield |
| March 5, 2022 | 81 mph | Charlie Bluff |
Homes in Rock County
Median build year in Rock County: 1970. 85.2% of 70,694 homes predate 2000. Houses permitted since 2014: 3,247, or 45.9 per 1,000 homes. Busiest year: 2021.
| pre-1940 | 19.1% |
|---|---|
| 1940s | 7.3% |
| 1950s | 10.9% |
| 1960s | 13.3% |
| 1970s | 15.3% |
| 1980s | 7.8% |
| 1990s | 11.6% |
| 2000s | 10.2% |
| 2010s | 3.9% |
| 2020+ | 0.7% |
| Year | Houses | All units |
|---|---|---|
| 2014 | 123 | 143 |
| 2015 | 184 | 216 |
| 2016 | 229 | 257 |
| 2017 | 242 | 378 |
| 2018 | 310 | 340 |
| 2019 | 321 | 644 |
| 2020 | 351 | 671 |
| 2021 | 361 | 617 |
| 2022 | 286 | 396 |
| 2023 | 223 | 313 |
| 2024 | 301 | 628 |
| 2025 | 316 | 388 |
Quick answers
How many hail reports has Rock County had?
NOAA logged 74 hail reports in Rock County, Wisconsin, from 2014 to June 2026.
How many days had hail of 1 inch or larger in Rock County?
25 days, including 4 days with hail of 1.75 inches or larger. The National Weather Service calls hail of 1 inch or larger severe.
What was the largest hail reported in Rock County?
2.75 inches (a baseball), reported on April 18, 2025.
Which month has the most hail in Rock County?
April has the most reports, 31% of the 74 in the record.
Does a hail day in the record mean my roof was damaged?
A counted day only means a spotter reported hail somewhere in the area. An inspection is the only way to know whether a roof was hit.
Next steps for Rock County
Rock County cities we cover
Next to Rock County in the Wisconsin ranking
- Outagamie County (68 reports)
Cite this page
Data version: NOAA Storm Events hail data, 2014 to June 2026, loaded October 6, 2026. All dataset versions. Download the table as CSV. Free to quote with credit under CC BY 4.0.
Source: NOAA Storm Events Database, public domain. Counts and tables on this page are free to reuse with credit to PickARoofer under CC BY 4.0.