The most recent reported hail day was 2025-07-29, 367 days ago. Custer County is hit in most years, often more than once. The largest stone on record here is 3 inches, a teacup and 3 times the National Weather Service's 1 inch severe criterion, reported on 2014-06-17 near Ismay.
Colored swath = NOAA MRMS radar-estimated hail size; dots = NOAA SPC reports in Montana. Radar-indicated, not a guarantee of damage.
The last hail here fell on 2025-07-29, around Horton. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Custer 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 43 separate hail days here since 2010 -- 2.5 a year over 17 years of record. Those days carry 97 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 2011, with 6 hail days. The last five years track the long-run rate, with 9 days since 2022.
Roof-killing hail is routine here: 12 of the 43 days reached 2 inches or more, 28% of them, the last on 2025-07-29. Those big days do not follow the county's usual calendar: most of them fall in June, not July. 17 of the 43 days reached golf-ball size, 1.75 inches or bigger.
Across the whole of Montana, see the Montana hail map and history.
Reports cluster nearest Miles City -- 19 of the county's 43 hail days -- then Ismay (9), Volborg (9), Mizpah (7) and Powderville (3). That one town is named on 44% of them. Beyond those, NOAA names Tusler, Kinsey, Shirley and Murn on more than one hail day apiece.
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| 28 WSW Ismay | 3 | 2.75″ |
| Miles City | 3 | 2.00″ |
| Volborg | 3 | 1.00″ |
| 1 S Tusler | 2 | 2.00″ |
| 4 Ne Miles City | 2 | 2.00″ |
The season runs June through August: 38 of the 43 hail days on record fall in those 3 months (88%). July is the single busiest month, with 19 of them (44%). That peak sits inside the window rather than at either end. Hail has also been reported in May and September, outside that window. Reports span 5 of the 12 calendar months; the other 7 have never produced one.
| Month | Hail days |
|---|---|
| May | 4 |
| June | 13 |
| July | 19 |
| August | 6 |
| September | 1 |
That day put 3 reports on the map, the biggest 2 inches near Horton. No hail day has been reported here yet this year.
| Date | Max hail | Reports |
|---|---|---|
| 2025-07-29 | 2.00″ | 3 |
| 2025-07-28 | 1.00″ | 1 |
| 2025-07-25 | 1.00″ | 1 |
| 2025-06-20 | 1.25″ | 3 |
| 2024-08-21 | 2.50″ | 1 |
| 2023-07-11 | 1.00″ | 1 |
| 2023-06-19 | 1.00″ | 1 |
| 2023-05-24 | 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 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: Prairie County (33 hail days), Rosebud County (50) and Fallon County (41). Custer County sits in between.
Prairie County · Rosebud County · Fallon County
Back to the Montana hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Custer County, Montana only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.