Forsyth, IL Weather & Growing Conditions
Tonight
70°F
Partly Cloudy
Partly cloudy, with a low around 70. East southeast wind around 9 mph, with gusts as high as 17 mph. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 70°F | Partly Cloudy | 9 mph ESE | 4% |
| Saturday | 90°F | Slight Chance Showers And Thunderstorms | 9 mph SSW | 19% |
| Saturday Night | 69°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 8 mph SSW | 23% |
| Sunday | 85°F | Chance Showers And Thunderstorms | 5 to 14 mph N | 51% |
| Sunday Night | 60°F | Chance Showers And Thunderstorms | 13 to 16 mph NE | 67% |
| Monday | 71°F | Showers And Thunderstorms Likely | 17 mph NE | 67% |
| Monday Night | 54°F | Showers And Thunderstorms Likely | 14 to 18 mph NE | 62% |
| Tuesday | 68°F | Chance Rain Showers | 17 mph NE | 35% |
| Tuesday Night | 52°F | Mostly Cloudy | 8 to 16 mph NNE | 7% |
| Wednesday | 70°F | Partly Sunny | 13 mph NNE | 2% |
| Wednesday Night | 53°F | Partly Cloudy | 5 to 13 mph NNE | 2% |
| Thursday | 71°F | Mostly Sunny | 6 to 12 mph NNE | 3% |
| Thursday Night | 54°F | Partly Cloudy | 5 to 10 mph NNE | 5% |
| Friday | 74°F | Mostly Sunny | 6 to 12 mph NNE | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Forsyth, IL
Last spring frost
Apr 14
First fall frost
Oct 24
Growing season
192 days
Hardiness zone
6a
Explore more for Forsyth, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Decatur Wtp, Il (6.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.