Hail — Grant, South Dakota
2025-08-21 · near Big Stone City, Grant, South Dakota
1
Magnitude
Wider weather episode
Storms moving south across northeast South Dakota produced hail and heavy rain, leading to flash flooding around the Watertown area.
The resultant runoff would also later result in flooding of the Big Sioux and surrounding tributaries around the Watertown and Castlewood areas.
View location on OpenStreetMap → (45.3100, -96.5100)
Source: NOAA Storm Events Database, event_id 1291018. Narrative written by the NWS forecast office that issued the report.