Monmouth, IL Weather & Growing Conditions
Today
87°F
Mostly Sunny
Mostly sunny, with a high near 87. South wind 5 to 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Mostly Sunny | 5 to 10 mph S | 1% |
| Tonight | 68°F | Chance Showers And Thunderstorms | 5 mph SE | 35% |
| Wednesday | 81°F | Showers And Thunderstorms Likely | 5 mph SW | 64% |
| Wednesday Night | 63°F | Showers And Thunderstorms | 0 to 5 mph N | 87% |
| Thursday | 80°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 0 to 5 mph NE | 63% |
| Thursday Night | 62°F | Partly Cloudy | 0 mph | 13% |
| Friday | 82°F | Mostly Sunny | 0 mph | 10% |
| Friday Night | 65°F | Mostly Clear | 0 to 5 mph SE | 12% |
| Saturday | 85°F | Sunny | 5 mph S | 10% |
| Saturday Night | 70°F | Mostly Clear | 5 to 10 mph S | 9% |
| Sunday | 87°F | Sunny | 10 mph SW | 9% |
| Sunday Night | 70°F | Partly Cloudy then Chance Showers And Thunderstorms | 5 to 10 mph S | 26% |
| Monday | 87°F | Chance Showers And Thunderstorms | 5 to 10 mph S | 26% |
| Monday Night | 71°F | Slight Chance Showers And Thunderstorms | 10 mph S | 29% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Monmouth, IL
Last spring frost
Apr 22
First fall frost
Oct 15
Growing season
174 days
Hardiness zone
5b
Explore more for Monmouth, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Monmouth, Il (2.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.