Harman US

River Sioux, IA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for River Sioux, a community in Harrison County, Iowa.

Overnight
68°F
Showers And Thunderstorms Likely
Showers and thunderstorms likely. Cloudy. Low around 68, with temperatures rising to around 71 overnight. Northwest wind around 6 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch possible.

7-day forecast for River Sioux

WhenTempForecastWindPrecip
Overnight 68°F Showers And Thunderstorms Likely 6 mph NW 74%
Saturday 75°F Showers And Thunderstorms Likely then Mostly Cloudy 5 to 9 mph NNW 56%
Saturday Night 60°F Slight Chance Rain Showers 10 mph N 19%
Sunday 64°F Chance Rain Showers 10 mph NNE 40%
Sunday Night 55°F Chance Rain Showers 6 to 9 mph NE 45%
Monday 59°F Rain Showers Likely 9 mph ENE 61%
Monday Night 50°F Chance Rain Showers then Mostly Cloudy 3 to 8 mph ENE 43%
Tuesday 61°F Partly Sunny 6 mph E 9%
Tuesday Night 46°F Partly Cloudy 5 mph ESE 1%
Wednesday 65°F Mostly Sunny 2 to 6 mph SE 3%
Wednesday Night 52°F Partly Cloudy then Chance Rain Showers 5 mph SE 30%
Thursday 66°F Chance Rain Showers 3 to 7 mph SE 31%
Thursday Night 56°F Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms 6 mph SE 21%
Friday 68°F Slight Chance Showers And Thunderstorms 3 to 7 mph SE 21%

Forecast source: National Weather Service (api.weather.gov) for River Sioux (41.802, -96.048). Updated through the day.

Growing snapshot for River Sioux

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

More local growing data for River Sioux: nearby ZIP 51545 weather · frost dates · planting calendar · Iowa frost dates

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Climate data from the nearest NOAA station, Little Sioux 2 Nw, Ia (2.5 mi from River Sioux). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.