Harman US

Onawa, IA Weather & Growing Conditions

Overnight
68°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 3am, then showers and thunderstorms likely. Mostly cloudy. Low around 68, with temperatures rising to around 71 overnight. West northwest wind around 7 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast

WhenTempForecastWindPrecip
Overnight 68°F Chance Showers And Thunderstorms 7 mph WNW 65%
Saturday 74°F Chance Showers And Thunderstorms then Mostly Cloudy 6 to 10 mph NNW 47%
Saturday Night 59°F Slight Chance Rain Showers then Mostly Cloudy 10 mph N 15%
Sunday 64°F Chance Rain Showers 8 to 12 mph NNE 37%
Sunday Night 55°F Chance Rain Showers 7 to 10 mph NE 53%
Monday 60°F Rain Showers Likely 9 mph ENE 62%
Monday Night 50°F Chance Rain Showers then Mostly Cloudy 3 to 9 mph ENE 42%
Tuesday 62°F Partly Sunny 3 to 7 mph E 8%
Tuesday Night 46°F Partly Cloudy 5 mph ESE 1%
Wednesday 65°F Mostly Sunny 2 to 7 mph SE 3%
Wednesday Night 52°F Partly Cloudy then Chance Rain Showers 6 mph SE 31%
Thursday 66°F Chance Rain Showers 7 mph SE 31%
Thursday Night 55°F Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms 6 mph SE 16%
Friday 69°F Slight Chance Showers And Thunderstorms then Mostly Cloudy 3 to 8 mph SE 16%

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

Growing snapshot for Onawa, IA

Last spring frost
May 1
First fall frost
Oct 3
Growing season
154 days
Hardiness zone
5a

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

Climate data from the nearest NOAA station, Onawa 3Nw, Ia (3.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.