Mendon, IL Weather & Growing Conditions
Tonight
73°F
Partly Cloudy
Partly cloudy, with a low around 73. South wind around 8 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 73°F | Partly Cloudy | 8 mph S | 12% |
| Saturday | 91°F | Partly Sunny | 8 mph SW | 8% |
| Saturday Night | 70°F | Chance Showers And Thunderstorms | 6 mph W | 41% |
| Sunday | 80°F | Showers And Thunderstorms Likely | 5 to 9 mph NW | 66% |
| Sunday Night | 62°F | Showers And Thunderstorms Likely | 12 mph NE | 71% |
| Monday | 68°F | Showers And Thunderstorms Likely | 12 mph NE | 71% |
| Monday Night | 57°F | Chance Showers And Thunderstorms | 10 mph NE | 47% |
| Tuesday | 65°F | Chance Rain Showers then Mostly Cloudy | 12 mph NE | 25% |
| Tuesday Night | 52°F | Mostly Cloudy | 6 to 9 mph NE | 6% |
| Wednesday | 69°F | Mostly Sunny | 7 mph NE | 0% |
| Wednesday Night | 55°F | Partly Cloudy | 6 mph NE | 0% |
| Thursday | 70°F | Mostly Sunny | 6 mph NE | 4% |
| Thursday Night | 57°F | Partly Cloudy | 5 mph NE | 5% |
| Friday | 72°F | Mostly Sunny | 6 mph NE | 6% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Mendon, IL
Last spring frost
Apr 14
First fall frost
Oct 23
Growing season
191 days
Hardiness zone
6a
Explore more for Mendon, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Quincy Rgnl Ap, Il (12.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.