Harman US

Mount Vernon, IA Weather & Growing Conditions

Tonight
67°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms between 11pm and 2am, then showers and thunderstorms. Mostly cloudy, with a low around 67. Southeast wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

7-day forecast

WhenTempForecastWindPrecip
Tonight 67°F Chance Showers And Thunderstorms 5 to 10 mph SE 82%
Saturday 82°F Showers And Thunderstorms Likely 5 to 10 mph S 73%
Saturday Night 63°F Showers And Thunderstorms 5 mph N 79%
Sunday 69°F Showers And Thunderstorms Likely 10 to 15 mph NE 68%
Sunday Night 57°F Showers And Thunderstorms Likely 10 to 15 mph NE 66%
Monday 64°F Rain Showers Likely 15 mph NE 57%
Monday Night 52°F Rain Showers Likely 10 to 15 mph NE 57%
Tuesday 62°F Chance Rain Showers 10 mph NE 31%
Tuesday Night 48°F Partly Cloudy 5 to 10 mph NE 7%
Wednesday 66°F Mostly Sunny 5 mph NE 1%
Wednesday Night 52°F Partly Cloudy 0 to 5 mph NE 3%
Thursday 69°F Mostly Sunny 0 to 5 mph NE 9%
Thursday Night 54°F Partly Cloudy 0 to 5 mph NE 7%
Friday 70°F Mostly Sunny 0 to 5 mph NE 5%

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

Growing snapshot for Mount Vernon, IA

Last spring frost
Apr 28
First fall frost
Oct 12
Growing season
166 days
Hardiness zone
5a

Explore more for Mount Vernon, IA: full frost dates · planting calendar · Iowa frost dates

Climate data from the nearest NOAA station, Cedar Rapids #1, Ia (10.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.