Knoxville, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Knoxville, a city in Knox County, Illinois.
This Afternoon
68°F
Light Rain
Rain and a chance of thunderstorms. Mostly cloudy, with a high near 68. South southeast wind around 17 mph, with gusts as high as 29 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Knoxville
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 68°F | Light Rain | 17 mph SSE | 90% |
| Tonight | 51°F | Light Rain | 10 to 17 mph S | 76% |
| Wednesday | 57°F | Slight Chance Light Rain 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 14 mph W | 23% |
| Thursday Night | 41°F | Chance Light Rain | 5 to 8 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 WNW | 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% |
Forecast source: National Weather Service (api.weather.gov) for Knoxville (40.907, -90.286). Updated through the day.
Growing snapshot for Knoxville
Last spring frost
Apr 21
First fall frost
Oct 20
Growing season
181 days
Hardiness zone
5b
More local growing data for Knoxville: nearby ZIP 61430 weather · frost dates · planting calendar · Illinois frost dates
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Climate data from the nearest NOAA station, Knoxville, Il (3.1 mi from Knoxville). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.