| Official Name: | Castlewood, South Dakota |
| Settlement Type: | Town |
| Motto: | "A Small Town With A Big Heart" |
| Mapsize: | 250px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | South Dakota |
| Subdivision Type2: | County |
| Subdivision Name2: | Hamlin |
| Leader Title: | Mayor |
| Leader Name: | Brian Ries |
| Established Title: | Founded |
| Established Date: | 1881 |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 2.98 |
| Area Land Km2: | 2.98 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 1.15 |
| Area Land Sq Mi: | 1.15 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Est: | 707 |
| Pop Est As Of: | 2022 |
| Population Total: | 698 |
| Population Density Km2: | 237.3 |
| Population Density Sq Mi: | 615 |
| Population Metro: | 35073 |
| Timezone: | Central (CST) |
| Utc Offset: | –6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | –5 |
| Elevation M: | 514 |
| Elevation Ft: | 1686 |
| Coordinates: | 44.7242°N -97.0308°W |
| Postal Code Type: | ZIP Code |
| Postal Code: | 57223 |
| Area Code: | 605 |
| Blank Name: | FIPS code |
| Blank Info: | 46-10500 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 1267313 |
| Blank2 Name: | Sales tax |
| Blank2 Info: | 6.2%[2] |
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.[3] and was estimated to be 707 in 2022.
Castlewood was platted in 1881 when the railroad was extended to that point.[4] The city was named Castlewood after a place mentioned in the 1857 novel The Virginians by William Makepeace Thackeray. A post office has been in operation in Castlewood since September 27, 1882.[5]
A destructive EF2 tornado hit the town on May 12, 2022, destroying several structures, damaging homes, and injuring one person.[6]
Castlewood is located along the Big Sioux River.[7]
According to the United States Census Bureau, the city has a total area of 1.15sqmi, all land.[1]
Castlewood has a dry-winter humid continental climate (Köppen Dwb), with four distinct seasons and a high seasonal temperature variation. The winters are long and harsh, with an annual average extreme minimum temperature of -28.1 °F (-33.4 °C), placing it within the 4a USDA Hardiness Zone (-30°F to -25°F) or (-34.4°C to -31.7°C).[8] 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.
As of the 2020 census, there were 698 people and 270 households, and 180 families residing in the town.[9] There were 296 housing units.
As of the 2010 census, there were 627 people in 260 households, including 158 families, in the city. The population density was 545.2PD/sqmi. There were 292 housing units at an average density of 253.9/sqmi. The racial makeup of the city was 96.5% White, 0.5% African American, 0.5% Native American, 0.2% Asian, 1.4% from other races, and 1.0% from two or more races. Hispanic or Latino of any race were 1.8%.
Of the 260 households 35.4% had children under the age of 18 living with them, 50.4% were married couples living together, 6.9% had a female householder with no husband present, 3.5% had a male householder with no wife present, and 39.2% were non-families. 33.5% of households were one person and 17.6% were one person aged 65 or older. The average household size was 2.41 and the average family size was 3.16.
The median age was 36.2 years. 28.2% of residents were under the age of 18; 7.4% were between the ages of 18 and 24; 26% were from 25 to 44; 24% were from 45 to 64; and 14.5% were 65 or older. The gender makeup of the city was 50.2% male and 49.8% female.
As of the 2000 census, there were 666 people in 253 households, including 185 families, in the city. The population density was 585.9sp=usNaNsp=us. There were 265 housing units at an average density of 233.1sp=usNaNsp=us. The racial makeup of the city was 98.95% White, 0.45% Native American, and 0.60% from two or more races. Hispanic or Latino of any race were 0.30%. 38.1% were of German, 18.4% Norwegian, 9.9% Dutch, 6.8% American, 6.4% Irish and 5.6% English ancestry.
Of the 253 households 40.3% had children under the age of 18 living with them, 60.5% were married couples living together, 7.9% had a female householder with no husband present, and 26.5% were non-families. 24.1% of households were one person and 14.2% were one person aged 65 or older. The average household size was 2.57 and the average family size was 3.06.
The age distribution was 28.5% under the age of 18, 8.1% from 18 to 24, 26.6% from 25 to 44, 20.6% from 45 to 64, and 16.2% 65 or older. The median age was 35 years. For every 100 females, there were 94.7 males. For every 100 females age 18 and over, there were 91.9 males.
The median income was $36,607 and the median income for a family was $41,806. Males had a median income of $29,688 versus $20,750 for females. The per capita income for the city was $17,682. About 7.7% of families and 7.1% of the population were below the poverty line, including 12.0% of those under age 18 and 6.7% of those age 65 or over.