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Potomac, IL Weather & Growing Conditions

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

This Afternoon
84°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms. Mostly cloudy, with a high near 84. South southeast wind around 6 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast for Potomac

WhenTempForecastWindPrecip
This Afternoon 84°F Slight Chance Showers And Thunderstorms 6 mph SSE 16%
Tonight 68°F Mostly Cloudy then Slight Chance Showers And Thunderstorms 6 mph S 15%
Sunday 80°F Chance Showers And Thunderstorms 5 to 12 mph N 55%
Sunday Night 59°F Chance Showers And Thunderstorms 13 mph NE 53%
Monday 69°F Showers And Thunderstorms Likely 13 mph ENE 57%
Monday Night 54°F Chance Rain Showers 12 mph ENE 40%
Tuesday 67°F Chance Rain Showers 12 mph NE 36%
Tuesday Night 53°F Slight Chance Rain Showers then Mostly Cloudy 6 to 12 mph NNE 23%
Wednesday 68°F Mostly Cloudy 6 to 9 mph NNE 10%
Wednesday Night 54°F Mostly Cloudy 2 to 9 mph N 3%
Thursday 71°F Partly Sunny 6 mph NNE 3%
Thursday Night 55°F Mostly Cloudy 5 mph NNE 6%
Friday 74°F Partly Sunny 2 to 6 mph NNE 6%
Friday Night 53°F Partly Cloudy 5 mph NE 4%

Forecast source: National Weather Service (api.weather.gov) for Potomac (40.307, -87.798). Updated through the day.

Growing snapshot for Potomac

Last spring frost
Apr 22
First fall frost
Oct 19
Growing season
180 days
Hardiness zone
6a

More local growing data for Potomac: nearby ZIP 61865 weather · frost dates · planting calendar · Illinois frost dates

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Climate data from the nearest NOAA station, Hoopeston, Il (12.9 mi from Potomac). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.