Mendon, IL Weather & Growing Conditions
Today
88°F
Sunny
Sunny, with a high near 88. South wind around 7 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 88°F | Sunny | 7 mph S | 0% |
| Tonight | 70°F | Partly Cloudy | 3 to 7 mph S | 14% |
| Wednesday | 85°F | Scattered Showers And Thunderstorms | 6 mph S | 52% |
| Wednesday Night | 67°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 7 mph N | 89% |
| Thursday | 82°F | Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 mph SE | 89% |
| Thursday Night | 66°F | Partly Cloudy | 3 mph SE | 6% |
| Friday | 85°F | Mostly Sunny | 3 mph S | 7% |
| Friday Night | 68°F | Chance Showers And Thunderstorms | 3 mph S | 30% |
| Saturday | 88°F | Slight Chance Showers And Thunderstorms then Sunny | 3 to 7 mph SW | 24% |
| Saturday Night | 73°F | Mostly Clear | 5 to 10 mph S | 6% |
| Sunday | 90°F | Sunny | 9 to 13 mph SW | 4% |
| Sunday Night | 73°F | Mostly Clear | 12 mph S | 13% |
| Monday | 91°F | Mostly Sunny | 12 mph SW | 13% |
| Monday Night | 73°F | Slight Chance Showers And Thunderstorms | 9 mph S | 25% |
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 Aug 4, 2026.