Winnebago, IL Weather & Growing Conditions
Tonight
56°F
Rain
Rain. Cloudy. Low around 56, with temperatures rising to around 60 overnight. South wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 56°F | Rain | 15 mph S | 85% |
| Wednesday | 59°F | Chance Rain then Chance Rain Showers | 15 mph SSW | 41% |
| Wednesday Night | 45°F | Chance Rain Showers | 15 mph SW | 29% |
| Thursday | 54°F | Chance Rain Showers | 10 to 15 mph WSW | 53% |
| Thursday Night | 40°F | Chance Rain Showers | 10 to 15 mph NW | 30% |
| Friday | 50°F | Slight Chance Rain Showers then Partly Sunny | 10 to 15 mph N | 15% |
| Friday Night | 32°F | Partly Cloudy | 0 to 10 mph NNW | 2% |
| Saturday | 51°F | Mostly Sunny | 0 to 5 mph WNW | 2% |
| Saturday Night | 32°F | Partly Cloudy | 5 mph WSW | 4% |
| Sunday | 58°F | Mostly Sunny then Slight Chance Rain | 5 to 10 mph W | 15% |
| Sunday Night | 33°F | Mostly Clear | 5 to 10 mph W | 4% |
| Monday | 61°F | Sunny | 5 to 15 mph SW | 1% |
| Monday Night | 38°F | Mostly Clear | 5 to 10 mph W | 0% |
| Tuesday | 61°F | Sunny | 5 to 10 mph WNW | 1% |
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 Nov 4, 2026.