Monticello, IL Weather & Growing Conditions
Today
85°F
Patchy Fog then Sunny
Patchy fog before 9am. Sunny, with a high near 85. South wind around 6 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 85°F | Patchy Fog then Sunny | 6 mph S | 0% |
| Tonight | 65°F | Mostly Clear | 6 mph SSE | 0% |
| Wednesday | 85°F | Mostly Sunny | 5 to 8 mph S | 8% |
| Wednesday Night | 67°F | Chance Showers And Thunderstorms | 7 mph S | 81% |
| Thursday | 81°F | Showers And Thunderstorms | 7 mph SSW | 81% |
| Thursday Night | 65°F | Chance Showers And Thunderstorms | 6 mph S | 33% |
| Friday | 82°F | Mostly Sunny | 5 mph SSW | 13% |
| Friday Night | 66°F | Slight Chance Showers And Thunderstorms | 3 mph SSW | 24% |
| Saturday | 85°F | Slight Chance Rain Showers then Mostly Sunny | 7 mph SSW | 18% |
| Saturday Night | 69°F | Mostly Clear | 5 to 9 mph SSW | 14% |
| Sunday | 87°F | Sunny | 9 to 14 mph SSW | 8% |
| Sunday Night | 71°F | Mostly Clear | 13 mph SSW | 11% |
| Monday | 88°F | Slight Chance Showers And Thunderstorms | 13 mph SSW | 16% |
| Monday Night | 72°F | Slight Chance Showers And Thunderstorms | 12 mph SW | 27% |
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 Aug 4, 2026.