Castlewood, SD Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Castlewood, a city in Hamlin County, South Dakota.
This Afternoon
49°F
Light Rain Likely
Rain likely. Cloudy. High near 49, with temperatures falling to around 46 in the afternoon. North northwest wind around 23 mph, with gusts as high as 35 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Castlewood
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 49°F | Light Rain Likely | 23 mph NNW | 70% |
| Tonight | 36°F | Light Rain | 15 to 20 mph NNW | 88% |
| Wednesday | 43°F | Light Rain | 20 mph NNW | 88% |
| Wednesday Night | 33°F | Chance Light Rain then Mostly Cloudy | 14 to 17 mph NNW | 53% |
| Thursday | 43°F | Partly Sunny | 12 to 15 mph N | 4% |
| Thursday Night | 28°F | Mostly Cloudy | 1 to 10 mph NE | 0% |
| Friday | 45°F | Partly Sunny | 1 to 5 mph SE | 0% |
| Friday Night | 29°F | Partly Cloudy | 5 mph SSW | 0% |
| Saturday | 54°F | Mostly Sunny | 5 to 13 mph WSW | 3% |
| Saturday Night | 33°F | Partly Cloudy | 6 to 9 mph W | 4% |
| Sunday | 56°F | Sunny | 6 to 10 mph WSW | 3% |
| Sunday Night | 37°F | Mostly Clear | 8 mph SSW | 0% |
| Monday | 58°F | Mostly Sunny | 8 to 16 mph W | 0% |
| Monday Night | 35°F | Mostly Clear | 5 to 9 mph WNW | 0% |
Forecast source: National Weather Service (api.weather.gov) for Castlewood (44.724, -97.031). Updated through the day.
Growing snapshot for Castlewood
Last spring frost
May 10
First fall frost
Sep 27
Growing season
139 days
Hardiness zone
4a
More local growing data for Castlewood: nearby ZIP 57223 weather · frost dates · planting calendar · South Dakota frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Castlewood, Sd (1.9 mi from Castlewood). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.