Hail history for Janesville, Wisconsin
NOAA hail reports in and within about 5 km (3 miles) of Janesville since 1975, with preliminary reports to November 3, 2026.
Readout · Janesville
- Last hail
- Apr 17, 2026
- 1.50 in, ping pong ball size
- Hail days, last 5 years
- 8
- since Nov 3, 2021 · 19 reports
- Largest ever
- 2.25 in
- hen egg · Aug 2, 2011
48 reports on 31 days since 1975 · #8 of 271 Wisconsin places
Hail map · Janesville
- Under 1 in
- 1–1.75 in
- 1.75–2.5 in
- 2.5–4 in
- 4 in +
- No size
For homeowners
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What the record says about Janesville
The latest hail report in and around Janesville is from April 17, 2026, 1.50 in (ping pong ball size). Since November 3, 2021 there have been 8 separate hail days; the biggest stones in that time were 1.50 in on April 17, 2026.
Over the 20 years 2006–2025, Janesville logged 31 reports on 20 hail days, about 1.6 reports a year. That is 3.4 times the median Wisconsin town on this site (0.5 a year) and ranks #8 of 271 Wisconsin cities and towns on this site for all-time reports. Janesville accounts for 28% of the 174 reports filed in Rock County.
6% of reports with a size were 2 inches (hen egg) or larger, against 6% for the median Wisconsin town on this site. The largest hail on record here is 2.25 in (hen egg) on August 2, 2011 near Downtown Janesville.
Reports were up 144% in 2016–2025 (22) compared with 2006–2015 (9). The busiest year was 2024, with 8 reports on 4 days. Hail here peaks in May (25% of reports); 60% fall between April and June.
Reports a year 2006–2025 average
- Janesville 1.6
- Rock County 5.0
- Median Wisconsin town on this site 0.5
Hail days 2006–2025
- Janesville 20
- Rock County 56
- Median Wisconsin town on this site 7
Share 2 in or larger of sized reports
- Janesville 6%
- Rock County 9%
- Median Wisconsin town on this site 6%
Hail over time
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 5 | 5 | |||||||||||
| 2025 | 5 | 5 | |||||||||||
| 2024 | 1 | 1 | 1 | 5 | 8 | ||||||||
| 2023 | 0 | ||||||||||||
| 2022 | 1 | 1 | |||||||||||
| 2021 | 0 | ||||||||||||
| 2020 | 1 | 1 | |||||||||||
| 2019 | 1 | 1 | |||||||||||
| 2018 | 2 | 2 | |||||||||||
| 2017 | 2 | 2 |
Hail days since Nov 3, 2021
| Date | Reports | Largest | Storm page |
|---|---|---|---|
| Apr 17, 2026 | 1 | 1.50 in | — |
| Apr 2, 2026 | 4 | 1.50 in | — |
| Aug 16, 2025 | 5 | 1.50 in | — |
| Jun 25, 2024 | 5 | 1.25 in | — |
| May 7, 2024 | 1 | 0.75 in | — |
| Mar 4, 2024 | 1 | 0.75 in | — |
| Feb 8, 2024 | 1 | 0.75 in | — |
| Sep 20, 2022 | 1 | 0.88 in | — |
Largest hail on record
| Date | Size | Location | County | Time · source |
|---|---|---|---|---|
| Aug 2, 2011 | 2.25 inhen egg | Downtown Janesville | Rock | 16:05 local · NCEI |
| Jun 25, 1998 | 2.00 inhen egg | Janesville | Rock | 18:48 local · NCEI |
| Jun 4, 1975 | 2.00 inhen egg | — | Rock | 19:45 local · NCEI |
| Oct 23, 2001 | 1.75 ingolf ball | 2 E Afton | Rock | 21:57 local · NCEI |
| Apr 17, 2026 | 1.50 inping pong ball | 0.51 W Downtown Janesville | Rock | 17:12 local · NCEI |
Sizes filed before 1996 are often rough estimates (round numbers like 7.00 or 8.00 in) without an exact spot; they are shown as NOAA filed them.
Size of every report
- Under 1 in 21 44%
- 1–2 in 24 50%
- 2 in + 3 6%
Most recent reports
| Date | Size | Location | County | Time · source |
|---|---|---|---|---|
| Apr 17, 2026 | 1.50 inping pong ball | 0.51 W Downtown Janesville | Rock | 17:12 local · NCEI |
| Apr 2, 2026 | 0.88 innickel | 3.49 N Downtown Janesville | Rock | 18:07 local · NCEI |
| Apr 2, 2026 | 0.75 inpenny | 2.63 ENE Downtown Janesville | Rock | 17:27 local · NCEI |
| Apr 2, 2026 | 1.50 inping pong ball | 2.15 NNE Downtown Janesville | Rock | 17:22 local · NCEI |
| Apr 2, 2026 | 1.25 inhalf dollar | 0.78 NW Downtown Janesville | Rock | 17:19 local · NCEI |
| Aug 16, 2025 | 1.00 inquarter | 2.94 NNE Downtown Janesville | Rock | 13:25 local · NCEI |
| Aug 16, 2025 | 1.00 inquarter | 1.38 N Downtown Janesville | Rock | 13:22 local · NCEI |
| Aug 16, 2025 | 1.00 inquarter | 2.07 N Janesville Airport | Rock | 13:21 local · NCEI |
| Aug 16, 2025 | 1.50 inping pong ball | 1.67 WNW Downtown Janesville | Rock | 13:20 local · NCEI |
| Aug 16, 2025 | 1.00 inquarter | 2.31 NNW Downtown Janesville | Rock | 13:20 local · NCEI |
| Jun 25, 2024 | 1.25 inhalf dollar | 2.57 NE Downtown Janesville | Rock | 18:55 local · NCEI |
| Jun 25, 2024 | 1.00 inquarter | 2.81 S Milton | Rock | 18:55 local · NCEI |
Hail history near Janesville
- Milton 12 km · 13
- Edgerton 18 km · 27
- Beloit 18 km · 20
- Lake Koshkonong 20 km · 15
- Evansville 25 km · 18
- Whitewater 28 km · 17
- Fort Atkinson 30 km · 20
- Brodhead 31 km · 12
Questions about hail in Janesville
How often does it hail in Janesville, Wisconsin?
48 hail reports have been logged in and within about 5 km (3 miles) of Janesville since 1975. Over the 20 years 2006–2025 that averages 1.6 reports a year. That ranks #8 of 271 Wisconsin places by number of reports.
When is hail season in Janesville?
Most reports come in May, June, August. May alone accounts for 25% of all reports.
What is the largest hail recorded in Janesville?
2.25 in (hen egg size) on August 2, 2011 near Downtown Janesville. 6% of reports here were 2 inches or larger.
When did it last hail in Janesville?
The most recent report in this data is from April 17, 2026 (1.50 in). Final NOAA data runs to July 31, 2026; preliminary NWS reports run to November 3, 2026.
How many hail storms has Janesville had in the last five years?
8 separate days with hail reports since November 3, 2021, adding up to 19 reports. The most recent was April 17, 2026.
Where does this hail data come from?
Hail reports come from the NOAA NCEI Storm Events Database, which the National Weather Service compiles from spotter, public, law enforcement and media reports. Recent days use preliminary NWS Local Storm Reports via the Iowa Environmental Mesonet until NOAA publishes final data. Only reported hail is counted, so areas with fewer people tend to have fewer reports.