Harman US

Osco, IL Weather & Growing Conditions

Overnight
68°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms before 4am, then patchy fog and a chance of showers and thunderstorms. Mostly cloudy. Low around 68, with temperatures rising to around 70 overnight. Southeast wind around 10 mph. Chance of precipitation is 30%.

7-day forecast

WhenTempForecastWindPrecip
Overnight 68°F Slight Chance Showers And Thunderstorms 10 mph SE 29%
Saturday 82°F Patchy Fog 5 to 10 mph SE 73%
Saturday Night 66°F Chance Showers And Thunderstorms then Showers And Thunderstorms 5 to 10 mph W 91%
Sunday 71°F Patchy Fog 10 to 15 mph NE 75%
Sunday Night 58°F Chance Showers And Thunderstorms 15 to 20 mph NE 49%
Monday 64°F Rain Showers Likely 15 mph NE 63%
Monday Night 53°F Chance Rain Showers 15 mph NE 48%
Tuesday 62°F Slight Chance Rain Showers 15 mph NE 23%
Tuesday Night 49°F Partly Cloudy 5 to 15 mph NE 8%
Wednesday 66°F Mostly Sunny 10 mph NE 2%
Wednesday Night 52°F Partly Cloudy 5 to 10 mph NE 1%
Thursday 68°F Mostly Sunny 5 to 10 mph NE 5%
Thursday Night 54°F Partly Cloudy 5 mph NE 4%
Friday 72°F Mostly Sunny 5 to 10 mph NE 3%

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

Growing snapshot for Osco, IL

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

Explore more for Osco, IL: full frost dates · planting calendar · Illinois frost dates

Climate data from the nearest NOAA station, Geneseo, Il (8.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.