Osco, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Osco, a community in Henry County, Illinois.
Today
86°F
Mostly Sunny
Mostly sunny. High near 86, with temperatures falling to around 84 in the afternoon. Southwest wind 5 to 10 mph.
7-day forecast for Osco
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 86°F | Mostly Sunny | 5 to 10 mph SW | 3% |
| Tonight | 68°F | Showers And Thunderstorms Likely | 5 mph E | 57% |
| Wednesday | 79°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 5 mph NE | 78% |
| Wednesday Night | 63°F | Showers And Thunderstorms | 5 mph N | 79% |
| Thursday | 79°F | Slight Chance Showers And Thunderstorms | 5 mph NE | 54% |
| Thursday Night | 62°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 0 to 5 mph E | 15% |
| Friday | 81°F | Mostly Sunny | 0 to 5 mph S | 9% |
| Friday Night | 65°F | Mostly Clear | 5 mph S | 10% |
| Saturday | 84°F | Sunny | 5 to 10 mph SW | 9% |
| Saturday Night | 71°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 5 to 15 mph S | 15% |
| Sunday | 86°F | Slight Chance Showers And Thunderstorms then Sunny | 10 to 15 mph SW | 15% |
| Sunday Night | 70°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph S | 33% |
| Monday | 85°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 10 to 15 mph S | 33% |
| Monday Night | 71°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 10 to 15 mph SW | 34% |
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
Alpha
Andover
Annawan
Atkinson
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 Aug 4, 2026.