Knoxville, IL Weather & Growing Conditions
Today
84°F
Slight Chance Rain Showers then Mostly Cloudy
A slight chance of rain showers before noon. Mostly cloudy, with a high near 84. South southeast wind around 8 mph, with gusts as high as 16 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Slight Chance Rain Showers then Mostly Cloudy | 8 mph SSE | 18% |
| Tonight | 67°F | Showers And Thunderstorms Likely | 2 to 6 mph WSW | 88% |
| Sunday | 73°F | Showers And Thunderstorms Likely | 3 to 15 mph NNE | 72% |
| Sunday Night | 58°F | Chance Showers And Thunderstorms | 13 to 16 mph NE | 58% |
| Monday | 65°F | Showers And Thunderstorms Likely | 16 mph ENE | 63% |
| Monday Night | 53°F | Chance Rain Showers | 10 to 15 mph NE | 50% |
| Tuesday | 63°F | Chance Rain Showers | 14 mph NE | 36% |
| Tuesday Night | 49°F | Partly Cloudy | 6 to 12 mph NNE | 8% |
| Wednesday | 67°F | Mostly Sunny | 7 to 10 mph NNE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 2 to 7 mph NNE | 1% |
| Thursday | 69°F | Partly Sunny | 6 mph NNE | 6% |
| Thursday Night | 54°F | Partly Cloudy | 5 mph NE | 4% |
| Friday | 73°F | Mostly Sunny | 2 to 7 mph NE | 4% |
| Friday Night | 54°F | Partly Cloudy | 5 mph ENE | 3% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Knoxville, IL
Last spring frost
Apr 21
First fall frost
Oct 20
Growing season
181 days
Hardiness zone
5b
Explore more for Knoxville, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Knoxville, Il (3.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.