Monticello, IL Weather & Growing Conditions
Overnight
58°F
Chance Light Rain
A chance of rain. Mostly cloudy, with a low around 58. South southwest wind around 15 mph, with gusts as high as 22 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 58°F | Chance Light Rain | 15 mph SSW | 38% |
| Wednesday | 62°F | Slight Chance Light Rain then Slight Chance Drizzle | 13 to 16 mph SW | 20% |
| Wednesday Night | 44°F | Slight Chance Drizzle then Mostly Cloudy | 12 mph SW | 10% |
| Thursday | 61°F | Partly Sunny | 12 to 16 mph WSW | 13% |
| Thursday Night | 42°F | Mostly Cloudy | 9 mph NW | 11% |
| Friday | 53°F | Partly Sunny | 10 to 14 mph NNW | 9% |
| Friday Night | 33°F | Partly Cloudy | 5 to 10 mph NNW | 0% |
| Saturday | 53°F | Sunny | 7 mph NW | 0% |
| Saturday Night | 31°F | Partly Cloudy | 5 mph WNW | 1% |
| Sunday | 58°F | Sunny | 5 to 10 mph WNW | 1% |
| Sunday Night | 33°F | Clear | 3 to 7 mph W | 0% |
| Monday | 63°F | Sunny | 3 to 9 mph SW | 0% |
| Monday Night | 38°F | Clear | 7 mph SW | 0% |
| Tuesday | 66°F | Sunny | 7 mph WNW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Monticello, IL
Last spring frost
Apr 23
First fall frost
Oct 13
Growing season
170 days
Hardiness zone
6a
Explore more for Monticello, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Champaign 9 Sw, Il (11.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.