Harman US

Mount Vernon, SD Weather & Growing Conditions

Today
67°F
Patchy Drizzle then Cloudy
Patchy drizzle and patchy fog before 11am. Cloudy, with a high near 67. North wind 10 to 15 mph.

7-day forecast

WhenTempForecastWindPrecip
Today 67°F Patchy Drizzle then Cloudy 10 to 15 mph N 12%
Tonight 55°F Cloudy 10 to 15 mph NNE 8%
Sunday 65°F Cloudy then Chance Rain Showers 10 to 15 mph NE 32%
Sunday Night 51°F Rain Showers 10 to 15 mph ENE 75%
Monday 62°F Rain Showers 10 mph E 75%
Monday Night 46°F Mostly Cloudy 5 to 10 mph ESE 5%
Tuesday 66°F Partly Sunny 5 to 15 mph SE 4%
Tuesday Night 48°F Partly Cloudy 10 to 15 mph SE 5%
Wednesday 69°F Partly Sunny then Slight Chance Rain Showers 15 to 20 mph SSE 15%
Wednesday Night 52°F Chance Rain Showers 15 mph SSE 38%
Thursday 71°F Chance Showers And Thunderstorms 15 mph SSE 38%
Thursday Night 54°F Slight Chance Rain Showers 10 to 15 mph SE 16%
Friday 73°F Slight Chance Rain Showers then Partly Sunny 10 to 15 mph SE 16%
Friday Night 56°F Mostly Cloudy then Slight Chance Rain Showers 15 mph SE 19%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Mount Vernon, SD

Last spring frost
Apr 27
First fall frost
Oct 11
Growing season
167 days
Hardiness zone
5a

Explore more for Mount Vernon, SD: full frost dates · planting calendar · South Dakota frost dates

Climate data from the nearest NOAA station, Mitchell, Sd (10.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.