Jefferson, SD Weather & Growing Conditions
Today
71°F
Patchy Smoke
Patchy smoke and a chance of showers and thunderstorms before 10am, then patchy smoke and scattered showers and thunderstorms between 10am and 1pm, then patchy smoke and showers and thunderstorms between 1pm and 3pm, then scattered showers and thunderstorms between 3pm and 4pm, then patchy smoke and scattered showers and thunderstorms. Mostly cloudy, with a high near 71. North wind 5 to 15 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 71°F | Patchy Smoke | 5 to 15 mph N | 82% |
| Tonight | 56°F | Patchy Smoke then Mostly Cloudy | 0 to 5 mph N | 47% |
| Wednesday | 76°F | Partly Sunny | 0 to 5 mph E | 4% |
| Wednesday Night | 54°F | Mostly Clear | 0 to 5 mph SSE | 1% |
| Thursday | 81°F | Mostly Sunny | 0 to 10 mph S | 0% |
| Thursday Night | 62°F | Mostly Clear | 5 to 10 mph S | 2% |
| Friday | 87°F | Sunny | 5 to 10 mph SSW | 3% |
| Friday Night | 66°F | Mostly Clear | 5 to 10 mph S | 10% |
| Saturday | 90°F | Sunny | 5 to 15 mph S | 4% |
| Saturday Night | 69°F | Mostly Clear | 10 to 15 mph SSE | 14% |
| Sunday | 90°F | Mostly Sunny | 10 to 15 mph SE | 13% |
| Sunday Night | 70°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 10 to 15 mph ESE | 16% |
| Monday | 89°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph E | 16% |
| Monday Night | 69°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph E | 21% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Jefferson, SD
Last spring frost
Apr 29
First fall frost
Oct 7
Growing season
161 days
Hardiness zone
5a
Explore more for Jefferson, SD: full frost dates · planting calendar · South Dakota frost dates
Climate data from the nearest NOAA station, Sioux City Ang, Ia (16.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.