Castlewood, SD Weather & Growing Conditions
Today
71°F
Partly Sunny
Partly sunny, with a high near 71. Northwest wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 71°F | Partly Sunny | 10 mph NW | 2% |
| Tonight | 52°F | Mostly Clear | 2 to 7 mph SSW | 0% |
| Wednesday | 77°F | Sunny | 5 to 13 mph SW | 0% |
| Wednesday Night | 58°F | Mostly Clear | 7 to 10 mph SSW | 1% |
| Thursday | 82°F | Sunny | 10 to 16 mph SSW | 4% |
| Thursday Night | 61°F | Mostly Clear | 12 mph SSW | 4% |
| Friday | 85°F | Sunny | 12 mph SSW | 11% |
| Friday Night | 61°F | Mostly Clear | 5 to 8 mph SSE | 11% |
| Saturday | 85°F | Sunny | 6 to 14 mph SSE | 6% |
| Saturday Night | 63°F | Slight Chance Showers And Thunderstorms | 13 mph ESE | 21% |
| Sunday | 82°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 13 mph E | 19% |
| Sunday Night | 63°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 10 mph E | 23% |
| Monday | 82°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 10 to 15 mph ENE | 23% |
| Monday Night | 62°F | Slight Chance Showers And Thunderstorms | 9 to 15 mph NE | 15% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Castlewood, SD
Last spring frost
May 10
First fall frost
Sep 27
Growing season
139 days
Hardiness zone
4a
Explore more for Castlewood, SD: full frost dates · planting calendar · South Dakota frost dates
Climate data from the nearest NOAA station, Castlewood, Sd (1.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.