Castlewood is a city in Hamlin County, South Dakota, United States. It is part of the Watertown, South Dakota Micropolitan Statistical Area. The population was 698 at the 2020 census, and was estimated to be 707 in 2022. The city was named Castlewood after a place mentioned in the 1857 novel The Virginians by William Makepeace Thackeray.
A destructive EF2 tornado hit the town on May 12, 2022, destroying several structures, damaging homes, and injuring one person.
Geography
Castlewood is located along the Big Sioux River.
According to the United States Census Bureau, the city has a total area of , all land. Summers are warm, with an average temperature of 69.4 °F (20.8 °C) in July, and experience a high level of precipitation compared to the dry winters.