Johnson County, Iowa: hail history 2014–2026
Johnson County ranks #6 of 67 Iowa counties for hail: 175.0 reports per 1,000 square miles, 109 reports in all. Hail reached 1 inch on 25 days and 1.75 inches on 6. Record: 2.75 inches (a baseball), March 10, 2026 near Oasis.
- 109reports
- 25days, 1 in+
- 6days, 1.75 in+
- 2.75 inlargest stone
Hail since my roof went on: Johnson County
Year by year
| Year | Reports | Days 1 in+ | Days 1.75 in+ | Largest |
|---|---|---|---|---|
| 2014 | 14 | 2 | 1 | 1.75 in |
| 2015 | 3 | 0 | 0 | 0.75 in |
| 2016 | 1 | 0 | 0 | 0.75 in |
| 2017 | 20 | 5 | 0 | 1.5 in |
| 2018 | 7 | 1 | 0 | 1 in |
| 2020 | 11 | 2 | 1 | 1.75 in |
| 2023 | 15 | 5 | 1 | 1.75 in |
| 2024 | 14 | 5 | 1 | 1.75 in |
| 2025 | 3 | 1 | 0 | 1 in |
| 2026 (Jan–Jun) | 21 | 4 | 2 | 2.75 in |
2017 was the busiest year (20 reports) and 2019 the quietest (0). 8 reports a year in 2014 to 2019 against 7 in 2020 to 2025: close to flat. 2026 stands at 21 through June, already past the full-year average of 7. Days with 1-inch stones average 1.8 per full year.
Johnson County: reports by month
| Jan | 0 |
|---|---|
| Feb | 13 |
| Mar | 17 |
| Apr | 17 |
| May | 20 |
| Jun | 12 |
| Jul | 18 |
| Aug | 3 |
| Sep | 1 |
| Oct | 6 |
| Nov | 2 |
| Dec | 0 |
No month stands out. May is highest at 18%, with July behind it at 17%. March to May alone bring 50%. 38 of 109 reports fell outside April to September.
Largest stone: 2.75 inches
Reported hail locations, Johnson County
- 611 to 1.74 in
- 81.75 to 2.74 in, golf ball to tennis ball
- 12.75 in and up, baseball
Largest plotted stone: 2.75 in. Bigger dots are bigger stones.
70 reports of 1 inch or larger have coordinates. Each dot is a reported location, not a storm path.
Sources: NOAA, Census county outlineJohnson County’s ten biggest hail days
| Date | Size | Reports | Place |
|---|---|---|---|
| March 10, 2026 | 2.75 in, a baseball | 12 | Oasis |
| July 11, 2020 | 1.75 in, a golf ball | 10 | North Liberty |
| June 16, 2014 | 1.75 in, a golf ball | 5 | Iowa City |
| June 25, 2024 | 1.75 in, a golf ball | 3 | Solon |
| March 31, 2023 | 1.75 in, a golf ball | 2 | North Liberty |
| April 2, 2026 | 1.75 in, a golf ball | 1 | Iowa City Muni Arpt |
| February 28, 2017 | 1.5 in, a ping-pong ball | 11 | Oasis |
| May 7, 2023 | 1.5 in, a ping-pong ball | 8 | Oasis |
| April 14, 2026 | 1.5 in, a ping-pong ball | 5 | Iowa City |
| July 11, 2017 | 1.5 in, a ping-pong ball | 2 | Oasis |
“Severe thunderstorms developed across eastern Iowa and northwest Illinois Saturday, July 11, producing widespread wind damage and very large hail.”
NWS report, July 11, 2020
“Golf ball size hail was reported at the intersection of Highway 6 and Scott boulevard.”
NWS report, June 16, 2014
Tornadoes and wind in Johnson County
16 tornadoes on record in Johnson County; the strongest listed is EF2, 16.93 miles long, near Cosgrove. Top gust: 83 mph near Iowa City Muni Arpt.
| Date | Rating | Path length | Width | Near |
|---|---|---|---|---|
| March 31, 2023 | EF2 | 16.93 mi | 75 yd | Cosgrove · 0 deaths, 2 injured |
| March 31, 2023 | EF2 | 14.69 mi | 100 yd | Hills |
| March 31, 2023 | EF2 | 4.19 mi | 75 yd | Solon |
| May 24, 2024 | EF1 | 11.49 mi | 150 yd | River Jct |
| May 24, 2019 | EF1 | 10.76 mi | 75 yd | Williamstown |
| May 24, 2024 | EF1 | 9.84 mi | 100 yd | Amish |
| May 24, 2024 | EF1 | 4.06 mi | 75 yd | Lone Tree |
| March 31, 2023 | EF1 | 2.24 mi | 700 yd | Amish |
| Date | Gust | Near |
|---|---|---|
| August 28, 2018 | 83 mph | Iowa City Muni Arpt |
| August 28, 2018 | 82 mph | University Hgts |
| April 12, 2014 | 81 mph | Iowa City |
| April 27, 2014 | 81 mph | Iowa City |
| June 30, 2014 | 81 mph | North Liberty |
| August 10, 2020 | 81 mph | Oxford |
Homes in Johnson County
Median build year in Johnson County: 1991. 63.9% of 67,211 homes predate 2000. Houses permitted since 2014: 6,069, or 90.3 per 1,000 homes. Busiest year: 2014.
| pre-1940 | 9.7% |
|---|---|
| 1940s | 1.8% |
| 1950s | 5.2% |
| 1960s | 8.6% |
| 1970s | 12.4% |
| 1980s | 10.7% |
| 1990s | 15.3% |
| 2000s | 16.3% |
| 2010s | 18.3% |
| 2020+ | 1.6% |
| Year | Houses | All units |
|---|---|---|
| 2014 | 621 | 1,080 |
| 2015 | 436 | 1,248 |
| 2016 | 548 | 1,874 |
| 2017 | 585 | 1,274 |
| 2018 | 445 | 1,295 |
| 2019 | 401 | 1,094 |
| 2020 | 478 | 956 |
| 2021 | 602 | 1,104 |
| 2022 | 444 | 1,375 |
| 2023 | 484 | 1,236 |
| 2024 | 512 | 714 |
| 2025 | 513 | 1,241 |
Quick answers
How many hail reports has Johnson County had?
NOAA logged 109 hail reports in Johnson County, Iowa, from 2014 to June 2026.
How many days had hail of 1 inch or larger in Johnson County?
25 days, including 6 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 Johnson County?
2.75 inches (a baseball), reported on March 10, 2026.
Which month has the most hail in Johnson County?
May has the most reports, 18% of the 109 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 Johnson County
Johnson County cities we cover
Next to Johnson County in the Iowa ranking
- Story County (153 reports)
- Scott County (128 reports)
- Woodbury County (92 reports)
- Pottawattamie County (83 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.