The most recent reported hail day was 2025-07-20, 376 days ago. Slope County is hit in most years. The largest stone on record here is 3.75 inches and 3.8 times the National Weather Service's 1 inch severe criterion, reported on 2015-06-30 near Amidon.
Colored swath = NOAA MRMS radar-estimated hail size; dots = NOAA SPC reports in North Dakota. Radar-indicated, not a guarantee of damage.
The last hail here fell on 2025-07-20, around Amidon. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Slope 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 23 separate hail days here since 2010 -- 1.4 a year over 17 years of record. They carry 37 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 2016, with 4 hail days. The last five years have been quieter than the long run: 2 days since 2022, against 1.8 a year before that.
3 of the 23 days reached 2 inches or more -- 13%, or about one hail day in 8, the last on 2016-07-10. Those big days do not follow the county's usual calendar: most of them fall in June, not July. More than half of every hail day on record here -- 12 of 23 -- reached golf-ball size, 1.75 inches or bigger.
Across the whole of North Dakota, see the North Dakota hail map and history.
Reports cluster nearest Amidon -- 11 of the county's 23 hail days -- then Marmarth (5), Three V Crossing (5), Buffalo Springs (2) and New England (2). That one town is named on 48% of them. Beyond those, NOAA names Pretty Butte on more than one hail day apiece.
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| 5 W Marmarth | 3 | 1.75″ |
| 10 Sse Amidon | 2 | 1.75″ |
| 3 W Amidon | 2 | 1.75″ |
| 9 Nne Buffalo Springs | 2 | 1.75″ |
| Amidon | 2 | 1.50″ |
The season runs June through August: 20 of the 23 hail days on record fall in those 3 months (87%). July is the single busiest month, with 12 of them (52%). 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 | 1 |
| June | 5 |
| July | 12 |
| August | 3 |
| September | 2 |
That day put 1 report on the map, the biggest 1 inch near Amidon. No hail day has been reported here yet this year.
| Date | Max hail | Reports |
|---|---|---|
| 2025-07-20 | 1.00″ | 1 |
| 2024-06-15 | 1.00″ | 1 |
| 2021-09-02 | 1.00″ | 1 |
| 2021-07-08 | 1.75″ | 4 |
| 2019-08-03 | 1.75″ | 2 |
| 2018-07-21 | 1.75″ | 1 |
| 2018-06-26 | 1.50″ | 1 |
| 2017-07-20 | 1.00″ | 2 |
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 3.75 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: Bowman County (37 hail days), Golden Valley County (23), Billings County (23) and Fallon County, Montana (41). Slope County sits in between.
Bowman County · Golden Valley County · Billings County · Fallon County, Montana
Back to the North Dakota hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Slope County, North Dakota only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.