The most recent reported hail day was 2026-04-13, 109 days ago. Osceola County is hit in most years. The largest stone on record here is 1.75 inches, a golf ball and 1.8 times the National Weather Service's 1 inch severe criterion, reported on 2026-04-13 near Harris.
Colored swath = NOAA MRMS radar-estimated hail size; dots = NOAA SPC reports in Iowa. Radar-indicated, not a guarantee of damage.
The last hail here fell on 2026-04-13, around Harris. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Osceola County addresses inside a hail swath above your size threshold into a door-knock list you can export, scoped to your approved markets.
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See call-center options ->NOAA's Storm Prediction Center has logged 19 separate hail days here since 2010 -- 1.1 a year over 17 years of record. They carry 26 reports in total: most hail days here are logged from a single spot. 5 of those 17 years produced none at all. The busiest single year was 2025, with 2 hail days. The last five years have run hotter than the long-run rate: 9 days since 2022, against 0.8 a year before that.
No stone of 2 inches or more has ever been reported in Osceola County: all 19 hail days on record topped out below that. 5 of the 19 days reached golf-ball size, 1.75 inches or bigger.
Across the whole of Iowa, see the Iowa hail map and history.
Reports cluster nearest Sibley -- 6 of the county's 19 hail days -- then Ashton (5), Ocheyedan (4), Harris (3) and Melvin (3).
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| Ashton | 4 | 1.75″ |
| 6 Nne Sibley | 2 | 1.50″ |
| 1 S Harris | 1 | 1.75″ |
| 1 Se Harris | 1 | 1.75″ |
| 4 Nne Melvin | 1 | 1.75″ |
The season runs April through August: 17 of the 19 hail days on record fall in those 5 months (89%). July is the single busiest month, with 5 of them (26%). That peak sits inside the window rather than at either end. Hail has also been reported in September, outside that window. Reports span 6 of the 12 calendar months; the other 6 have never produced one.
| Month | Hail days |
|---|---|
| April | 3 |
| May | 2 |
| June | 2 |
| July | 5 |
| August | 5 |
| September | 2 |
That day put 4 reports on the map, the biggest 1.75 inches near Harris. 1 hail day has already been reported this year.
| Date | Max hail | Reports |
|---|---|---|
| 2026-04-13 | 1.75″ | 4 |
| 2025-09-21 | 1.00″ | 1 |
| 2025-04-28 | 1.25″ | 1 |
| 2024-07-10 | 1.00″ | 1 |
| 2024-07-04 | 1.00″ | 1 |
| 2023-07-13 | 1.00″ | 1 |
| 2023-07-10 | 1.75″ | 2 |
| 2022-08-18 | 1.00″ | 1 |
The colored swath is NOAA's MRMS radar estimate of the largest hail per ~1 km cell; the dots are SPC ground reports. Yellow is about an inch, red 1.5 to 2″, purple 2″ and up (hail size vs roof damage). On this county's worst day the reports reached 1.75 inches, which is the red band. Look up a street address with the hail history by address tool.
The nearest counties with a page of their own, over the state line included: O'Brien County (34 hail days), Dickinson County (22), Lyon County (30) and Nobles County, Minnesota (33). Every one of them takes more hail than Osceola County.
O'Brien County · Dickinson County · Lyon County · Nobles County, Minnesota
Back to the Iowa hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Osceola County, Iowa only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.