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Jefferson County, IA hail & severe wind history
91 storm reports on file for Jefferson County between 2010-06-01 and 2026-04-23 — 48 hail and 43 severe thunderstorm wind. That averages 5.4 reports a year, and May is the busiest month.
At a glance
- Most recent hail report: Apr 14, 2026 — 2" (hen egg), 0 mi N of Packwood.
- Hail was reported on 23 days since 2010 — about 1.4 hail days a year.
- Largest hail on record: 2" (hen egg) on Apr 14, 2026.
- Jefferson County has more hail reports than 34% of the 99 Iowa counties we cover.
Search every Jefferson County report
Check a single date first, or filter the full record below — pick a year, narrow to a month, or drag the hail-size slider to see only the larger stones (1", quarter size, is the National Weather Service severe threshold).
Loading Jefferson County storm reports…
Worst storm days in Jefferson County
| Date | Reports that day | Largest hail | Peak gust |
|---|---|---|---|
| 2014-05-11 | 8 | 1" (quarter) | — |
| 2011-09-03 | 5 | 1.75" (golf ball) | — |
| 2013-05-28 | 5 | 1" (quarter) | 70 mph |
| 2011-04-19 | 4 | 0.75" (penny) | — |
| 2026-03-10 | 3 | 1.5" (ping pong ball) | — |
| 2021-06-22 | 3 | 1" (quarter) | — |
| 2013-04-17 | 3 | 1" (quarter) | — |
| 2023-06-29 | 3 | — | 75 mph |
| 2020-08-10 | 3 | — | 70 mph |
| 2017-03-06 | 3 | — | 68 mph |
Reports by year
Report counts are driven partly by how many people were around to report a storm, so recent years tend to look busier than the early 2010s. Treat the trend as a reporting trend, not purely a weather trend.
Notable large-hail events (2" and up)
| Date | Size | Near | What was reported |
|---|---|---|---|
| 2026-04-14 | 2" hen egg | 0 mi N of Packwood | The time was estimated from radar data. |
When does hail hit Jefferson County?
Across 16 years of records, May produced the most reports (25), followed by the months either side of it. Monthly totals:
| Month | Reports | Share |
|---|---|---|
| January | 0 | 0.0% |
| February | 0 | 0.0% |
| March | 8 | 8.8% |
| April | 16 | 17.6% |
| May | 25 | 27.5% |
| June | 19 | 20.9% |
| July | 4 | 4.4% |
| August | 7 | 7.7% |
| September | 11 | 12.1% |
| October | 1 | 1.1% |
| November | 0 | 0.0% |
| December | 0 | 0.0% |
Neighboring counties
Counties that share a border with Jefferson County (U.S. Census county adjacency), where we have storm records:
| County | Storm reports | Largest hail |
|---|---|---|
| Wapello County, IA | 162 | 2.75" |
| Van Buren County, IA | 141 | 3" |
| Washington County, IA | 141 | 2.5" |
| Henry County, IA | 120 | 2" |
| Keokuk County, IA | 108 | 3" |
| Davis County, IA | 55 | 1.75" |
Common questions about hail in Jefferson County
- How often does it hail in Jefferson County?
- Hail was reported on 23 separate days between 2010 and 2026, about 1.4 days a year, with May the busiest month for storm reports. 30 reports were quarter size (1") or larger.
- Does a report here mean hail hit my street?
- Not necessarily. Each report is one observation tied to a nearby landmark, and a county can be large. Storms also go unreported where few people live. Use the date check above to see what was reported nearby, and treat it as a starting point.
- How big is a 1.75" hailstone?
- Forecasters describe hail by everyday objects: 1" is a quarter, 1.75" a golf ball, 2.75" a baseball. The sizes in these reports are estimates made by the person reporting, not lab measurements.
- Where do I get the official record?
- All reports here come from the NOAA NCEI Storm Events Database, which you can search directly. For anything formal, use NOAA’s own records rather than this page.
Look up another place
About these numbers
Every row above is a report filed with the National Weather Service and archived in the NOAA NCEI Storm Events Database (FIPS 19101). Reports are eyewitness, trained-spotter and damage-survey observations, so they cluster near roads and towns and miss storms over empty country. Hail sizes are estimates. Damage figures are preliminary as filed and are never revised in this archive. Use this page for background, not for an insurance claim, a legal filing, or a roof assessment — for those, get the official record from NOAA directly.