Forreston, IL Weather & Growing Conditions
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. 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 SW | 13% |
| Tonight | 66°F | Chance Showers And Thunderstorms | 0 to 5 mph WNW | 74% |
| Wednesday | 75°F | Showers And Thunderstorms Likely | 5 mph W | 74% |
| Wednesday Night | 60°F | Showers And Thunderstorms Likely | 0 to 5 mph NNW | 72% |
| Thursday | 78°F | Chance Rain Showers then Mostly Sunny | 0 to 5 mph NE | 33% |
| Thursday Night | 59°F | Mostly Clear | 0 mph | 8% |
| Friday | 80°F | Mostly Sunny | 0 to 5 mph SSE | 5% |
| Friday Night | 63°F | Mostly Clear | 0 to 5 mph S | 5% |
| Saturday | 83°F | Mostly Sunny | 5 to 10 mph SSW | 11% |
| Saturday Night | 68°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 21% |
| Sunday | 85°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph SSW | 21% |
| Sunday Night | 68°F | Chance Showers And Thunderstorms | 5 to 10 mph SSW | 41% |
| Monday | 84°F | Chance Showers And Thunderstorms | 5 to 10 mph SSW | 38% |
| Monday Night | 68°F | Chance Showers And Thunderstorms | 10 to 15 mph WNW | 43% |
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 Aug 4, 2026.