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Rio, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Rio, a village in Knox County, Illinois.

Overnight
68°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 68. South southeast wind around 7 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast for Rio

WhenTempForecastWindPrecip
Overnight 68°F Slight Chance Showers And Thunderstorms 7 mph SSE 23%
Saturday 84°F Chance Showers And Thunderstorms 9 mph SE 44%
Saturday Night 66°F Showers And Thunderstorms Likely 6 mph WSW 89%
Sunday 72°F Showers And Thunderstorms Likely 6 to 16 mph NNE 72%
Sunday Night 58°F Chance Showers And Thunderstorms 14 to 17 mph NE 55%
Monday 64°F Showers And Thunderstorms Likely 17 mph ENE 65%
Monday Night 52°F Chance Rain Showers 13 to 16 mph NE 51%
Tuesday 62°F Chance Rain Showers 13 to 16 mph NE 37%
Tuesday Night 48°F Partly Cloudy 7 to 13 mph NE 8%
Wednesday 66°F Mostly Sunny 10 mph NNE 1%
Wednesday Night 52°F Partly Cloudy 3 to 7 mph NE 1%
Thursday 68°F Mostly Sunny 7 mph NE 6%
Thursday Night 54°F Partly Cloudy 6 mph NE 4%
Friday 72°F Mostly Sunny 5 to 8 mph ENE 3%

Forecast source: National Weather Service (api.weather.gov) for Rio (41.109, -90.399). Updated through the day.

Growing snapshot for Rio

Last spring frost
Apr 20
First fall frost
Oct 19
Growing season
180 days
Hardiness zone
5b

More local growing data for Rio: nearby ZIP 61472 weather · frost dates · planting calendar · Illinois frost dates

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Climate data from the nearest NOAA station, Galesburg, Il (10.8 mi from Rio). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.