Forreston, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Forreston, a village in Ogle County, Illinois.
This Afternoon
67°F
Rain Showers
Rain showers. Cloudy. High near 67, with temperatures falling to around 65 in the afternoon. South wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Forreston
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 67°F | Rain Showers | 15 mph S | 84% |
| Tonight | 54°F | Rain Showers | 15 mph S | 83% |
| Wednesday | 58°F | Chance Rain Showers | 15 mph SSW | 43% |
| Wednesday Night | 45°F | Chance Rain Showers | 15 mph SW | 30% |
| Thursday | 54°F | Chance Rain Showers | 10 to 15 mph WSW | 53% |
| Thursday Night | 39°F | Chance Rain Showers | 5 to 10 mph NNW | 29% |
| Friday | 50°F | Partly Sunny | 10 to 15 mph N | 14% |
| Friday Night | 31°F | Partly Cloudy | 0 to 5 mph NNW | 1% |
| Saturday | 51°F | Mostly Sunny | 0 to 5 mph WNW | 2% |
| Saturday Night | 32°F | Partly Cloudy | 0 to 5 mph W | 4% |
| Sunday | 57°F | Mostly Sunny | 5 to 10 mph W | 13% |
| Sunday Night | 33°F | Mostly Clear | 5 mph WSW | 4% |
| Monday | 60°F | Sunny | 5 to 15 mph SW | 1% |
| Monday Night | 38°F | Mostly Clear | 5 to 10 mph W | 0% |
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 Nov 4, 2026.