Harman US

Plymouth, IL Weather & Growing Conditions

This Afternoon
86°F
Mostly Cloudy
Mostly cloudy, with a high near 86. Southwest wind around 7 mph.

7-day forecast

WhenTempForecastWindPrecip
This Afternoon 86°F Mostly Cloudy 7 mph SW 6%
Tonight 68°F Chance Showers And Thunderstorms 5 mph W 61%
Sunday 77°F Showers And Thunderstorms Likely 2 to 12 mph N 67%
Sunday Night 59°F Chance Showers And Thunderstorms then Showers And Thunderstorms Likely 8 to 13 mph NE 71%
Monday 66°F Showers And Thunderstorms Likely 9 to 13 mph ENE 73%
Monday Night 55°F Rain Showers Likely 8 to 12 mph NE 73%
Tuesday 64°F Chance Rain Showers 12 mph NE 31%
Tuesday Night 50°F Mostly Cloudy 3 to 9 mph NNE 3%
Wednesday 66°F Partly Sunny 5 to 8 mph NNE 1%
Wednesday Night 52°F Partly Cloudy 2 to 6 mph NNE 1%
Thursday 70°F Partly Sunny 1 to 5 mph NE 2%
Thursday Night 57°F Mostly Cloudy then Slight Chance Rain Showers 3 mph NE 15%
Friday 74°F Slight Chance Rain Showers then Partly Sunny 1 to 6 mph NE 15%
Friday Night 57°F Partly Cloudy 5 mph ENE 7%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Plymouth, IL

Last spring frost
Apr 13
First fall frost
Oct 22
Growing season
191 days
Hardiness zone
6a

Explore more for Plymouth, IL: full frost dates · planting calendar · Illinois frost dates

Climate data from the nearest NOAA station, Bentley, Il (13.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.