The most recent reported hail day was 2026-03-06, 147 days ago. Monona County is hit in most years. The largest stone on record here is 3.5 inches and 3.5 times the National Weather Service's 1 inch severe criterion, reported on 2024-06-12 near Onawa.
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 2026-03-06, around Blencoe. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Monona County addresses inside a hail swath above your size threshold into a door-knock list you can export, scoped to your approved markets.
Get free access Check an addressOur US-based call center calls the homeowners in this storm and books roof inspections straight onto your calendar. You work the storm; we fill the schedule. We dial -- you do not have to knock a single door.
See call-center options ->NOAA's Storm Prediction Center has logged 26 separate hail days here since 2010 -- 1.5 a year over 17 years of record. Those days carry 47 separate reports between them, two or three on a typical one. 3 of those 17 years produced none at all. The busiest single year was 2012, with 4 hail days. The last five years track the long-run rate, with 6 days since 2022.
Most hail here stays under 2 inches: only 2 of the 26 days on record passed it, 8%, the last on 2024-06-12. Those big days do not follow the county's usual calendar: most of them fall in May, not June. Golf-ball size is rarer still: 1.75 inches or more on 4 of the 26 days.
Across the whole of Iowa, see the Iowa hail map and history.
Reports cluster nearest Onawa -- 9 of the county's 26 hail days -- then Mapleton (7), Blencoe (7), Whiting (6) and Soldier (2). Beyond those, NOAA names Turin on more than one hail day apiece.
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| Blencoe | 5 | 1.50″ |
| Onawa | 4 | 1.50″ |
| Whiting | 3 | 2.75″ |
| Mapleton | 2 | 1.00″ |
| Soldier | 2 | 1.00″ |
The season runs April through August: 23 of the 26 hail days on record fall in those 5 months (88%). June is the single busiest month, with 7 of them (27%). That peak sits inside the window rather than at either end. Hail has also been reported in March and September, outside that window. Reports span 7 of the 12 calendar months; the other 5 have never produced one.
| Month | Hail days |
|---|---|
| March | 2 |
| April | 4 |
| May | 6 |
| June | 7 |
| July | 3 |
| August | 3 |
| September | 1 |
That day put 2 reports on the map, the biggest 1.5 inches near Blencoe. 1 hail day has already been reported this year.
| Date | Max hail | Reports |
|---|---|---|
| 2026-03-06 | 1.50″ | 2 |
| 2024-06-12 | 3.50″ | 3 |
| 2024-05-21 | 1.00″ | 1 |
| 2023-05-08 | 1.00″ | 1 |
| 2023-04-19 | 1.50″ | 3 |
| 2022-05-19 | 1.00″ | 1 |
| 2021-07-08 | 1.50″ | 1 |
| 2020-06-02 | 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 3.5 inches, which is the purple 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: Woodbury County (36 hail days), Harrison County (35), Crawford County (18), Burt County, Nebraska (22) and Thurston County, Nebraska (17). Monona County sits in between.
Woodbury County · Harrison County · Crawford County · Burt County, Nebraska · Thurston County, Nebraska
Back to the Iowa hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Monona County, Iowa only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.