Winnebago, IL Weather & Growing Conditions
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 5 to 10 mph SSW | 10% |
| Tonight | 65°F | Chance Showers And Thunderstorms | 5 to 10 mph W | 74% |
| Wednesday | 76°F | Showers And Thunderstorms Likely | 5 mph W | 74% |
| Wednesday Night | 59°F | Showers And Thunderstorms Likely | 0 to 5 mph NW | 68% |
| Thursday | 78°F | Chance Rain Showers then Mostly Sunny | 0 to 5 mph NE | 32% |
| Thursday Night | 58°F | Mostly Clear | 0 to 5 mph SE | 11% |
| Friday | 80°F | Mostly Sunny | 0 to 5 mph S | 6% |
| Friday Night | 61°F | Mostly Clear | 5 mph SSW | 6% |
| Saturday | 82°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 15% |
| Saturday Night | 68°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 22% |
| Sunday | 84°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph SW | 22% |
| Sunday Night | 67°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 to 10 mph SSW | 41% |
| Monday | 83°F | Chance Showers And Thunderstorms | 5 to 10 mph SSW | 40% |
| Monday Night | 67°F | Chance Showers And Thunderstorms | 10 mph WNW | 43% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Winnebago, IL
Last spring frost
Apr 24
First fall frost
Oct 17
Growing season
174 days
Hardiness zone
5b
Explore more for Winnebago, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Rockford Gtr Rockford Ap, Il (10.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.