Chillicothe, IL Weather & Growing Conditions
Overnight
68°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 68. South southeast wind around 5 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 |
|---|---|---|---|---|
| Overnight | 68°F | Slight Chance Showers And Thunderstorms | 5 mph SSE | 20% |
| Saturday | 84°F | Chance Showers And Thunderstorms | 7 mph ESE | 45% |
| Saturday Night | 68°F | Showers And Thunderstorms Likely | 5 mph WSW | 79% |
| Sunday | 74°F | Showers And Thunderstorms Likely | 3 to 14 mph NNE | 72% |
| Sunday Night | 58°F | Chance Showers And Thunderstorms | 12 to 15 mph NE | 54% |
| Monday | 66°F | Showers And Thunderstorms Likely | 15 mph ENE | 63% |
| Monday Night | 53°F | Chance Rain Showers | 10 to 15 mph NE | 45% |
| Tuesday | 65°F | Slight Chance Rain Showers | 14 mph NE | 22% |
| Tuesday Night | 51°F | Partly Cloudy | 6 to 13 mph NNE | 12% |
| Wednesday | 68°F | Mostly Sunny | 6 to 10 mph NNE | 4% |
| Wednesday Night | 53°F | Partly Cloudy | 2 to 9 mph NNE | 1% |
| Thursday | 70°F | Mostly Sunny | 3 to 7 mph NNE | 3% |
| Thursday Night | 54°F | Partly Cloudy | 2 to 6 mph NE | 3% |
| Friday | 73°F | Mostly Sunny | 3 to 7 mph NE | 3% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Chillicothe, IL
Last spring frost
Apr 20
First fall frost
Oct 17
Growing season
178 days
Hardiness zone
6a
Explore more for Chillicothe, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Lacon, Il (9.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.