Chillicothe, IL Weather & Growing Conditions
Today
87°F
Mostly Sunny
Mostly sunny, with a high near 87. South southwest wind around 6 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Mostly Sunny | 6 mph SSW | 0% |
| Tonight | 67°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 mph S | 22% |
| Wednesday | 83°F | Chance Showers And Thunderstorms | 2 to 6 mph SSW | 49% |
| Wednesday Night | 66°F | Showers And Thunderstorms | 5 mph N | 86% |
| Thursday | 81°F | Showers And Thunderstorms Likely | 5 mph SSE | 74% |
| Thursday Night | 64°F | Partly Cloudy | 0 to 3 mph SE | 13% |
| Friday | 83°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 2 mph SSE | 19% |
| Friday Night | 66°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 1 mph SSE | 19% |
| Saturday | 86°F | Mostly Sunny | 2 to 6 mph SSW | 10% |
| Saturday Night | 71°F | Mostly Clear | 3 to 7 mph S | 10% |
| Sunday | 88°F | Sunny | 8 to 12 mph SSW | 7% |
| Sunday Night | 72°F | Slight Chance Showers And Thunderstorms | 6 to 10 mph SSW | 24% |
| Monday | 88°F | Slight Chance Showers And Thunderstorms | 6 to 10 mph SSW | 24% |
| Monday Night | 72°F | Slight Chance Showers And Thunderstorms | 9 mph SW | 32% |
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 Aug 4, 2026.