Osco, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Osco, a community in Henry County, Illinois.

This Afternoon

80°F

Slight Chance Showers And Thunderstorms

A slight chance of showers and thunderstorms. Mostly cloudy. High near 80, with temperatures falling to around 78 in the afternoon. South wind 5 to 10 mph. Chance of precipitation is 20%.

7-day forecast for Osco

When	Temp	Forecast	Wind	Precip
This Afternoon	80°F	Slight Chance Showers And Thunderstorms	5 to 10 mph S	24%
Tonight	66°F	Chance Showers And Thunderstorms then Showers And Thunderstorms	5 mph S	89%
Sunday	70°F	Patchy Fog	10 to 15 mph N	72%
Sunday Night	58°F	Chance Rain Showers	15 mph NE	50%
Monday	63°F	Rain Showers Likely	15 mph NE	69%
Monday Night	54°F	Rain Showers Likely	15 mph NE	63%
Tuesday	61°F	Rain Showers Likely	15 mph NE	56%
Tuesday Night	50°F	Mostly Cloudy	5 to 15 mph NE	7%
Wednesday	64°F	Partly Sunny	10 mph NE	4%
Wednesday Night	52°F	Mostly Cloudy	5 to 10 mph NE	4%
Thursday	67°F	Partly Sunny	5 mph NE	5%
Thursday Night	56°F	Slight Chance Rain Showers	0 to 5 mph NE	15%
Friday	71°F	Partly Sunny	5 mph NE	11%
Friday Night	55°F	Partly Cloudy	5 mph NE	6%

Forecast source: National Weather Service (api.weather.gov) for Osco (41.347, -90.283). Updated through the day.

Growing snapshot for Osco

Last spring frost

Apr 20

First fall frost

Oct 20

Growing season

180 days

Hardiness zone

More local growing data for Osco: nearby ZIP 61274 weather · frost dates · planting calendar · Illinois frost dates

Nearby towns & communities

Alpha Andover Annawan Atkinson Bishop Hill Cambridge Cleveland Colona Galva Geneseo Hooppole Kewanee Lynn Center Ophiem Orion Swedona Woodhull

All Illinois locations ›

Climate data from the nearest NOAA station, Geneseo, Il (8.7 mi from Osco). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.