Winnebago, IL Weather & Growing Conditions
Today
76°F
Showers And Thunderstorms
Showers and thunderstorms before 1pm, then a chance of showers and thunderstorms between 1pm and 2pm, then showers and thunderstorms likely. Cloudy. High near 76, with temperatures falling to around 74 in the afternoon. South wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between three quarters and one inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 76°F | Showers And Thunderstorms | 5 to 10 mph S | 79% |
| Tonight | 60°F | Showers And Thunderstorms | 5 to 10 mph E | 92% |
| Sunday | 68°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 15 to 20 mph NE | 55% |
| Sunday Night | 54°F | Slight Chance Rain Showers | 15 mph NE | 23% |
| Monday | 63°F | Chance Rain Showers | 15 mph ENE | 42% |
| Monday Night | 48°F | Slight Chance Rain Showers | 10 to 15 mph NE | 20% |
| Tuesday | 62°F | Slight Chance Rain Showers then Partly Sunny | 10 to 15 mph NE | 15% |
| Tuesday Night | 47°F | Partly Cloudy | 5 to 15 mph NE | 8% |
| Wednesday | 65°F | Mostly Sunny | 10 to 15 mph NE | 3% |
| Wednesday Night | 49°F | Partly Cloudy | 5 to 10 mph NE | 1% |
| Thursday | 66°F | Mostly Sunny | 5 to 10 mph NE | 4% |
| Thursday Night | 50°F | Partly Cloudy | 5 mph NE | 4% |
| Friday | 70°F | Mostly Sunny | 5 to 10 mph NE | 4% |
| Friday Night | 49°F | Partly Cloudy | 5 mph ENE | 2% |
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 Sep 19, 2026.