Osco, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Osco, a community in Henry County, Illinois.
Overnight
52°F
Mostly Cloudy
Mostly cloudy. Low around 52, with temperatures rising to around 55 overnight. South wind 10 to 15 mph, with gusts as high as 25 mph.
7-day forecast for Osco
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 52°F | Mostly Cloudy | 10 to 15 mph S | 12% |
| Wednesday | 58°F | Slight Chance Rain Showers | 15 to 20 mph SW | 23% |
| Wednesday Night | 46°F | Mostly Cloudy | 15 mph SW | 10% |
| Thursday | 56°F | Chance Rain Showers | 10 to 15 mph W | 35% |
| Thursday Night | 42°F | Slight Chance Rain Showers then Mostly Cloudy | 10 mph NW | 22% |
| Friday | 50°F | Partly Sunny | 10 to 15 mph N | 7% |
| Friday Night | 32°F | Partly Cloudy | 0 to 5 mph N | 0% |
| Saturday | 52°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 34°F | Mostly Clear | 5 mph W | 2% |
| Sunday | 57°F | Sunny | 5 to 10 mph W | 1% |
| Sunday Night | 36°F | Clear | 5 mph W | 1% |
| Monday | 63°F | Sunny | 5 to 10 mph SW | 0% |
| Monday Night | 40°F | Mostly Clear | 5 to 10 mph W | 0% |
| Tuesday | 64°F | Sunny | 5 mph NW | 0% |
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
5b
More local growing data for Osco: nearby ZIP 61274 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
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Annawan
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Bishop Hill
Cambridge
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Galva
Geneseo
Hooppole
Kewanee
Lynn Center
Ophiem
Orion
Swedona
Woodhull
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 Nov 4, 2026.