Knoxville, IL Weather & Growing Conditions
Tonight
51°F
Light Rain Likely
Rain likely before 2am, then a slight chance of rain showers between 2am and 5am. Cloudy, with a low around 51. South southwest wind 8 to 13 mph, with gusts as high as 24 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 51°F | Light Rain Likely | 8 to 13 mph SSW | 68% |
| Wednesday | 57°F | Slight Chance Rain Showers then Mostly Cloudy | 16 mph SW | 22% |
| Wednesday Night | 45°F | Mostly Cloudy | 9 to 13 mph SW | 8% |
| Thursday | 56°F | Slight Chance Light Rain | 8 to 13 mph WSW | 23% |
| Thursday Night | 41°F | Chance Light Rain | 3 to 7 mph NW | 30% |
| Friday | 53°F | Slight Chance Light Rain | 6 to 10 mph N | 15% |
| Friday Night | 34°F | Partly Cloudy | 0 to 5 mph N | 1% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph NW | 3% |
| Saturday Night | 34°F | Partly Cloudy | 2 mph WNW | 3% |
| Sunday | 59°F | Sunny | 2 to 8 mph WNW | 11% |
| Sunday Night | 35°F | Mostly Clear | 5 mph W | 3% |
| Monday | 63°F | Sunny | 2 to 10 mph SW | 1% |
| Monday Night | 40°F | Mostly Clear | 3 to 7 mph W | 0% |
| Tuesday | 64°F | Sunny | 6 mph NW | 0% |
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 Nov 4, 2026.