Forreston, IL Weather & Growing Conditions
Overnight
63°F
Showers And Thunderstorms
Showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy, with a low around 63. East southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 63°F | Showers And Thunderstorms | 10 mph ESE | 100% |
| Saturday | 78°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 100% |
| Saturday Night | 61°F | Showers And Thunderstorms | 5 to 10 mph ESE | 93% |
| Sunday | 68°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 15 mph NE | 55% |
| Sunday Night | 54°F | Chance Rain Showers | 15 mph NE | 33% |
| Monday | 64°F | Chance Rain Showers | 15 mph ENE | 45% |
| Monday Night | 49°F | Slight Chance Rain Showers | 10 to 15 mph NE | 22% |
| Tuesday | 62°F | Slight Chance Rain Showers then Partly Sunny | 10 to 15 mph NE | 16% |
| Tuesday Night | 47°F | Partly Cloudy | 5 to 15 mph NE | 8% |
| Wednesday | 66°F | Mostly Sunny | 10 to 15 mph NE | 2% |
| Wednesday Night | 49°F | Partly Cloudy | 5 to 10 mph NE | 1% |
| Thursday | 67°F | Mostly Sunny | 5 to 10 mph NNE | 4% |
| Thursday Night | 50°F | Partly Cloudy | 0 to 5 mph NE | 4% |
| Friday | 70°F | Mostly Sunny | 5 to 10 mph NE | 3% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Forreston, IL
Last spring frost
Apr 29
First fall frost
Oct 7
Growing season
161 days
Hardiness zone
5b
Explore more for Forreston, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Polo 5Nw, Il (5.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.