Jefferson, SD Weather & Growing Conditions
Tonight
65°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 4am, then a chance of showers and thunderstorms. Mostly cloudy. Low around 65, with temperatures rising to around 69 overnight. North northwest wind 5 to 10 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 65°F | Chance Showers And Thunderstorms | 5 to 10 mph NNW | 37% |
| Saturday | 71°F | Slight Chance Showers And Thunderstorms then Cloudy | 5 to 10 mph NNW | 22% |
| Saturday Night | 58°F | Cloudy then Slight Chance Rain Showers | 10 mph N | 15% |
| Sunday | 65°F | Chance Rain Showers | 10 mph NE | 51% |
| Sunday Night | 54°F | Rain Showers Likely | 5 to 10 mph ENE | 63% |
| Monday | 60°F | Showers And Thunderstorms Likely | 10 mph ENE | 64% |
| Monday Night | 49°F | Chance Showers And Thunderstorms then Mostly Cloudy | 5 to 10 mph ENE | 38% |
| Tuesday | 63°F | Mostly Cloudy | 5 to 10 mph E | 5% |
| Tuesday Night | 49°F | Partly Cloudy | 5 mph ESE | 0% |
| Wednesday | 67°F | Partly Sunny | 5 to 10 mph SE | 11% |
| Wednesday Night | 53°F | Mostly Cloudy then Chance Rain Showers | 5 mph SE | 34% |
| Thursday | 67°F | Chance Rain Showers | 5 to 10 mph SSE | 34% |
| Thursday Night | 55°F | Slight Chance Rain Showers | 5 mph SE | 19% |
| Friday | 69°F | Slight Chance Rain Showers then Partly Sunny | 5 to 10 mph SE | 19% |
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 Sep 19, 2026.