Home › South Dakota › Union County
Union County, SD hail & severe wind history
118 storm reports on file for Union County between 2010-04-23 and 2026-05-31 — 44 hail and 74 severe thunderstorm wind. That averages 6.9 reports a year, and May is the busiest month.
At a glance
- Most recent hail report: May 31, 2026 — 1" (quarter), 4 mi SSW of Big Spgs.
- Hail was reported on 35 days since 2010 — about 2.1 hail days a year.
- Largest hail on record: 1.75" (golf ball) on Jun 2, 2025.
- Union County has more hail reports than 11% of the 66 South Dakota counties we cover.
Search every Union 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 Union County storm reports…
Worst storm days in Union County
| Date | Reports that day | Largest hail | Peak gust |
|---|---|---|---|
| 2022-05-12 | 10 | 0.75" (penny) | 85 mph |
| 2025-06-02 | 6 | 1.75" (golf ball) | 85 mph |
| 2012-05-27 | 6 | 1.5" (ping pong ball) | 70 mph |
| 2014-05-11 | 6 | — | 90 mph |
| 2025-07-28 | 5 | — | 81 mph |
| 2020-07-03 | 4 | — | 62 mph |
| 2024-05-20 | 3 | 1.75" (golf ball) | 90 mph |
| 2023-04-19 | 3 | 1.5" (ping pong ball) | — |
| 2025-07-29 | 3 | — | 68 mph |
| 2024-07-29 | 3 | — | 64 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.
When does hail hit Union County?
Across 17 years of records, May produced the most reports (35), followed by the months either side of it. Monthly totals:
| Month | Reports | Share |
|---|---|---|
| January | 0 | 0.0% |
| February | 0 | 0.0% |
| March | 1 | 0.8% |
| April | 8 | 6.8% |
| May | 35 | 29.7% |
| June | 25 | 21.2% |
| July | 32 | 27.1% |
| August | 7 | 5.9% |
| September | 6 | 5.1% |
| October | 4 | 3.4% |
| November | 0 | 0.0% |
| December | 0 | 0.0% |
Neighboring counties
Counties that share a border with Union County (U.S. Census county adjacency), where we have storm records:
| County | Storm reports | Largest hail |
|---|---|---|
| Woodbury County, IA | 290 | 2.75" |
| Sioux County, IA | 196 | 2.5" |
| Plymouth County, IA | 183 | 2.75" |
| Lincoln County, SD | 173 | 1.75" |
| Dixon County, NE | 111 | 4.25" |
| Clay County, SD | 102 | 3" |
| Dakota County, NE | 44 | 4.25" |
See all 66 South Dakota counties →
Common questions about hail in Union County
- How often does it hail in Union County?
- Hail was reported on 35 separate days between 2010 and 2026, about 2.1 days a year, with May the busiest month for storm reports. 33 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 46127). 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.