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.
Today
71°F
Patchy Smoke then Partly Sunny
Patchy smoke before 11am. Partly sunny, with a high near 71. Northwest wind 8 to 12 mph.
7-day forecast for Fort Thompson
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 71°F | Patchy Smoke then Partly Sunny | 8 to 12 mph NW | 8% |
| Tonight | 55°F | Partly Cloudy | 3 to 7 mph SSW | 1% |
| Wednesday | 81°F | Mostly Sunny | 3 to 12 mph S | 0% |
| Wednesday Night | 61°F | Partly Cloudy | 7 to 12 mph S | 4% |
| Thursday | 89°F | Sunny | 6 to 13 mph S | 4% |
| Thursday Night | 65°F | Mostly Clear | 7 to 10 mph S | 5% |
| Friday | 92°F | Sunny | 6 to 9 mph SSW | 4% |
| Friday Night | 65°F | Mostly Clear | 9 mph ESE | 5% |
| Saturday | 94°F | Sunny | 7 to 17 mph SE | 5% |
| Saturday Night | 65°F | Mostly Clear | 7 to 16 mph E | 9% |
| Sunday | 90°F | Mostly Sunny | 7 to 16 mph E | 6% |
| Sunday Night | 66°F | Chance Showers And Thunderstorms | 12 to 15 mph E | 32% |
| Monday | 88°F | Chance Showers And Thunderstorms then Partly Sunny | 10 to 15 mph ENE | 32% |
| Monday Night | 65°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph ENE | 20% |
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 Aug 4, 2026.