Onarga, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Onarga, a village in Iroquois County, Illinois.
Today
85°F
Patchy Fog then Mostly Sunny
Patchy fog before 8am. Mostly sunny, with a high near 85. South wind 0 to 5 mph.
7-day forecast for Onarga
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 85°F | Patchy Fog then Mostly Sunny | 0 to 5 mph S | 1% |
| Tonight | 63°F | Partly Cloudy | 0 to 5 mph S | 0% |
| Wednesday | 84°F | Partly Sunny then Slight Chance Showers And Thunderstorms | 0 to 5 mph SSW | 23% |
| Wednesday Night | 66°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 0 mph | 84% |
| Thursday | 81°F | Showers And Thunderstorms | 0 to 5 mph SSW | 84% |
| Thursday Night | 63°F | Chance Showers And Thunderstorms | 0 mph | 49% |
| Friday | 82°F | Mostly Sunny | 0 mph | 11% |
| Friday Night | 64°F | Slight Chance Showers And Thunderstorms | 0 mph | 21% |
| Saturday | 85°F | Mostly Sunny | 0 to 5 mph SSW | 13% |
| Saturday Night | 68°F | Mostly Clear | 0 to 5 mph SSW | 12% |
| Sunday | 87°F | Mostly Sunny | 5 to 10 mph SSW | 10% |
| Sunday Night | 70°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 mph SSW | 21% |
| Monday | 87°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 21% |
| Monday Night | 69°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 mph SW | 34% |
Forecast source: National Weather Service (api.weather.gov) for Onarga (40.715, -88.011). Updated through the day.
Growing snapshot for Onarga
Last spring frost
Apr 25
First fall frost
Oct 20
Growing season
175 days
Hardiness zone
5b
More local growing data for Onarga: nearby ZIP 60955 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Ashkum
Beaverville
Buckley
Cissna Park
Clifton
Crescent City
Danforth
Donovan
Gilman
Iroquois
Loda
Martinton
Milford
Papineau
Sheldon
Thawville
Watseka
Wellington
Woodland
Climate data from the nearest NOAA station, Piper City, Il (11 mi from Onarga). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.