Harman US

Harper, IA Weather & Growing Conditions

Today
82°F
Chance Rain Showers
A chance of rain showers before 1pm, then a chance of showers and thunderstorms between 1pm and 4pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 82. Southwest wind 5 to 10 mph. Chance of precipitation is 30%.

7-day forecast

WhenTempForecastWindPrecip
Today 82°F Chance Rain Showers 5 to 10 mph SW 34%
Tonight 63°F Chance Showers And Thunderstorms then Showers And Thunderstorms 5 to 10 mph NW 84%
Sunday 68°F Showers And Thunderstorms 10 to 15 mph NE 78%
Sunday Night 57°F Showers And Thunderstorms Likely 15 mph NE 60%
Monday 62°F Rain Showers Likely 15 mph NE 60%
Monday Night 51°F Chance Rain Showers 10 to 15 mph NE 45%
Tuesday 60°F Chance Rain Showers then Partly Sunny 10 to 15 mph NE 39%
Tuesday Night 46°F Partly Cloudy 5 to 10 mph NE 4%
Wednesday 64°F Mostly Sunny 5 mph NE 0%
Wednesday Night 51°F Partly Cloudy 5 mph NE 2%
Thursday 66°F Partly Sunny 5 mph NE 7%
Thursday Night 54°F Partly Cloudy 5 mph E 6%
Friday 69°F Mostly Sunny 5 mph E 6%
Friday Night 55°F Partly Cloudy 5 mph E 8%

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

Growing snapshot for Harper, IA

Last spring frost
Apr 24
First fall frost
Oct 15
Growing season
172 days
Hardiness zone
5b

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

Climate data from the nearest NOAA station, Sigourney, Ia (8.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.