Harman US

Harmon, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Harmon, a village in Lee County, Illinois.

This Afternoon
78°F
Showers And Thunderstorms
Showers and thunderstorms before 5pm, then a chance of showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy, with a high near 78. South southeast wind 5 to 10 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.

7-day forecast for Harmon

WhenTempForecastWindPrecip
This Afternoon 78°F Showers And Thunderstorms 5 to 10 mph SSE 88%
Tonight 63°F Showers And Thunderstorms Likely then Showers And Thunderstorms 5 to 10 mph ENE 95%
Sunday 70°F Showers And Thunderstorms Likely 10 to 15 mph NE 58%
Sunday Night 56°F Chance Showers And Thunderstorms 15 mph NE 40%
Monday 65°F Chance Rain Showers 15 mph ENE 50%
Monday Night 51°F Chance Rain Showers 10 to 15 mph NE 29%
Tuesday 64°F Slight Chance Rain Showers then Partly Sunny 10 to 15 mph NE 19%
Tuesday Night 48°F Partly Cloudy 5 to 15 mph NE 10%
Wednesday 67°F Mostly Sunny 5 to 10 mph NE 2%
Wednesday Night 50°F Partly Cloudy 5 to 10 mph NE 1%
Thursday 69°F Mostly Sunny 5 mph NNE 4%
Thursday Night 52°F Partly Cloudy 0 to 5 mph NE 4%
Friday 72°F Mostly Sunny 5 mph NE 2%
Friday Night 52°F Partly Cloudy 0 to 5 mph ENE 2%

Forecast source: National Weather Service (api.weather.gov) for Harmon (41.723, -89.554). Updated through the day.

Growing snapshot for Harmon

Last spring frost
Apr 24
First fall frost
Oct 14
Growing season
172 days
Hardiness zone
5b

More local growing data for Harmon: nearby ZIP 61042 weather · frost dates · planting calendar · Illinois frost dates

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Climate data from the nearest NOAA station, Walnut, Il (9.5 mi from Harmon). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.