Forreston, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Forreston, a village in Ogle County, Illinois.
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 for Forreston
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 5 to 10 mph SW | 12% |
| Tonight | 65°F | Chance Showers And Thunderstorms | 0 to 5 mph W | 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 | 6% |
| Friday Night | 63°F | Mostly Clear | 0 to 5 mph S | 6% |
| Saturday | 83°F | Mostly Sunny | 5 to 10 mph SSW | 10% |
| 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) for Forreston (42.127, -89.578). Updated through the day.
Growing snapshot for Forreston
Last spring frost
Apr 29
First fall frost
Oct 7
Growing season
161 days
Hardiness zone
5b
More local growing data for Forreston: nearby ZIP 61030 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Baileyville
Byron
Creston
Davis Junction
Hillcrest
Holcomb
Kings
Leaf River
Monroe Center
Mount Morris
Oregon
Polo
Rochelle
Stillman Valley
Climate data from the nearest NOAA station, Polo 5Nw, Il (5.9 mi from Forreston). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.