River Sioux, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for River Sioux, a community in Harrison County, Iowa.
Today
75°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 2pm, then showers and thunderstorms between 2pm and 4pm, then patchy smoke and a chance of showers and thunderstorms. Mostly cloudy. High near 75, with temperatures falling to around 73 in the afternoon. North wind around 14 mph, with gusts as high as 22 mph. Chance of precipitation is 80%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for River Sioux
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 75°F | Chance Showers And Thunderstorms | 14 mph N | 78% |
| Tonight | 59°F | Patchy Smoke | 3 to 12 mph NNE | 62% |
| Wednesday | 74°F | Patchy Smoke | 6 mph ENE | 37% |
| Wednesday Night | 55°F | Mostly Clear | 1 to 5 mph SE | 2% |
| Thursday | 81°F | Sunny | 1 to 7 mph SE | 1% |
| Thursday Night | 63°F | Mostly Clear | 7 mph SSE | 4% |
| Friday | 86°F | Sunny | 5 to 10 mph S | 4% |
| Friday Night | 68°F | Mostly Clear | 5 to 9 mph S | 7% |
| Saturday | 91°F | Sunny | 5 to 17 mph S | 3% |
| Saturday Night | 71°F | Mostly Clear | 10 to 17 mph S | 10% |
| Sunday | 91°F | Mostly Sunny | 9 to 14 mph SSE | 7% |
| Sunday Night | 71°F | Slight Chance Showers And Thunderstorms | 12 to 15 mph SSE | 18% |
| Monday | 91°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph SSE | 18% |
| Monday Night | 72°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 10 to 16 mph ESE | 17% |
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
Nearby towns & communities
California Junction
Dunlap
Little Sioux
Logan
Loveland
Magnolia
Missouri Valley
Modale
Mondamin
Persia
Pisgah
Woodbine
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 Aug 4, 2026.