Potomac, IL Weather & Growing Conditions
This Afternoon
85°F
Mostly Cloudy
Mostly cloudy, with a high near 85. South wind around 6 mph. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 85°F | Mostly Cloudy | 6 mph S | 14% |
| Tonight | 68°F | Mostly Cloudy | 6 mph SSW | 13% |
| Sunday | 81°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 5 to 12 mph N | 51% |
| Sunday Night | 58°F | Chance Showers And Thunderstorms | 12 mph NE | 47% |
| Monday | 69°F | Showers And Thunderstorms Likely | 13 mph ENE | 58% |
| Monday Night | 54°F | Chance Rain Showers | 12 mph ENE | 42% |
| Tuesday | 67°F | Chance Rain Showers | 13 mph NE | 39% |
| Tuesday Night | 53°F | Slight Chance Rain Showers then Mostly Cloudy | 6 to 12 mph NNE | 22% |
| Wednesday | 69°F | Mostly Cloudy | 9 mph NNE | 10% |
| Wednesday Night | 54°F | Mostly Cloudy | 3 to 9 mph N | 3% |
| Thursday | 71°F | Partly Sunny | 7 mph NNE | 3% |
| Thursday Night | 55°F | Mostly Cloudy | 2 to 6 mph NNE | 6% |
| Friday | 74°F | Partly Sunny | 3 to 7 mph NNE | 6% |
| Friday Night | 54°F | Partly Cloudy | 2 to 6 mph NE | 4% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Potomac, IL
Last spring frost
Apr 21
First fall frost
Oct 20
Growing season
181 days
Hardiness zone
6a
Explore more for Potomac, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Danville, Il (9.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.