Castlewood, SD Weather & Growing Conditions
Today
63°F
Areas Of Fog
Areas of fog and a slight chance of drizzle. Mostly cloudy, with a high near 63. Northeast wind 8 to 13 mph, with gusts as high as 22 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 63°F | Areas Of Fog | 8 to 13 mph NE | 12% |
| Tonight | 50°F | Patchy Fog then Mostly Cloudy | 7 to 13 mph NNE | 8% |
| Sunday | 65°F | Mostly Cloudy | 12 to 15 mph NE | 8% |
| Sunday Night | 47°F | Cloudy | 9 to 13 mph ENE | 14% |
| Monday | 64°F | Slight Chance Rain Showers | 12 mph E | 16% |
| Monday Night | 43°F | Partly Cloudy | 5 to 8 mph E | 5% |
| Tuesday | 65°F | Mostly Sunny | 5 to 13 mph SE | 3% |
| Tuesday Night | 44°F | Partly Cloudy | 9 mph SE | 2% |
| Wednesday | 68°F | Mostly Sunny | 8 to 15 mph SSE | 7% |
| Wednesday Night | 49°F | Chance Rain Showers | 10 mph SSE | 30% |
| Thursday | 70°F | Chance Rain Showers | 10 to 14 mph SSE | 30% |
| Thursday Night | 52°F | Mostly Cloudy then Slight Chance Rain Showers | 9 mph SSE | 15% |
| Friday | 72°F | Slight Chance Rain Showers then Partly Sunny | 7 to 14 mph SSE | 15% |
| Friday Night | 53°F | Mostly Cloudy then Slight Chance Rain Showers | 12 mph SSE | 19% |
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 Sep 19, 2026.