Fort Thompson, SD Weather & Growing Conditions
Tonight
59°F
Patchy Fog
Patchy fog. Cloudy, with a low around 59. North northeast wind around 9 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 59°F | Patchy Fog | 9 mph NNE | 5% |
| Saturday | 66°F | Patchy Fog then Cloudy | 12 mph NNE | 7% |
| Saturday Night | 55°F | Cloudy then Slight Chance Rain Showers | 12 mph NE | 23% |
| Sunday | 63°F | Chance Rain Showers | 14 mph ENE | 54% |
| Sunday Night | 52°F | Rain Showers | 12 mph ENE | 91% |
| Monday | 61°F | Rain Showers | 10 mph E | 85% |
| Monday Night | 49°F | Slight Chance Rain Showers then Mostly Cloudy | 9 mph ESE | 23% |
| Tuesday | 66°F | Partly Sunny | 9 to 16 mph SE | 11% |
| Tuesday Night | 53°F | Mostly Cloudy | 15 mph SE | 14% |
| Wednesday | 71°F | Chance Rain Showers | 18 mph SSE | 30% |
| Wednesday Night | 55°F | Chance Rain Showers | 12 to 16 mph SE | 31% |
| Thursday | 72°F | Chance Rain Showers then Partly Sunny | 10 mph SE | 27% |
| Thursday Night | 56°F | Partly Cloudy | 9 mph SE | 9% |
| Friday | 73°F | Partly Sunny | 10 to 15 mph SE | 9% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Fort Thompson, SD
Last spring frost
May 6
First fall frost
Oct 5
Growing season
152 days
Hardiness zone
4b
Explore more for Fort Thompson, SD: full frost dates · planting calendar · South Dakota frost dates
Climate data from the nearest NOAA station, Lake Sharpe Prj, Sd (4.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.