Fort Thompson, SD Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Fort Thompson, a community in Buffalo County, South Dakota.
This Afternoon
70°F
Cloudy
Cloudy, with a high near 70. North wind around 5 mph.
7-day forecast for Fort Thompson
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 70°F | Cloudy | 5 mph N | 3% |
| Tonight | 57°F | Cloudy then Patchy Fog | 3 to 8 mph N | 4% |
| Saturday | 66°F | Patchy Fog then Cloudy | 8 to 12 mph NNE | 7% |
| Saturday Night | 54°F | Cloudy then Slight Chance Rain Showers | 8 to 12 mph NE | 17% |
| Sunday | 63°F | Chance Rain Showers | 13 mph ENE | 53% |
| Sunday Night | 51°F | Rain Showers | 8 to 12 mph ENE | 91% |
| Monday | 61°F | Rain Showers | 10 mph E | 86% |
| Monday Night | 48°F | Slight Chance Rain Showers then Mostly Cloudy | 6 to 10 mph ESE | 20% |
| Tuesday | 66°F | Partly Sunny | 8 to 16 mph SE | 11% |
| Tuesday Night | 52°F | Mostly Cloudy then Slight Chance Rain Showers | 14 mph SE | 15% |
| Wednesday | 71°F | Chance Rain Showers | 14 to 17 mph SSE | 31% |
| Wednesday Night | 55°F | Chance Rain Showers | 10 to 16 mph SSE | 31% |
| Thursday | 72°F | Chance Rain Showers then Partly Sunny | 10 mph SE | 28% |
| Thursday Night | 55°F | Partly Cloudy | 9 mph SE | 9% |
Forecast source: National Weather Service (api.weather.gov) for Fort Thompson (44.055, -99.405). Updated through the day.
Growing snapshot for Fort Thompson
Last spring frost
May 6
First fall frost
Oct 5
Growing season
152 days
Hardiness zone
4b
More local growing data for Fort Thompson: nearby ZIP 57339 weather · frost dates · planting calendar · South Dakota frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Lake Sharpe Prj, Sd (4.3 mi from Fort Thompson). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 18, 2026.