St. Charles, IL Weather & Growing Conditions
Tonight
62°F
Slight Chance Rain Showers then Chance Showers And Thunderstorms
A slight chance of rain showers before 1am, then a chance of showers and thunderstorms. Mostly cloudy, with a low around 62. East southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 50%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 62°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 5 to 10 mph ESE | 50% |
| Saturday | 77°F | Showers And Thunderstorms Likely | 5 to 10 mph SE | 86% |
| Saturday Night | 64°F | Showers And Thunderstorms Likely then Showers And Thunderstorms | 5 to 10 mph NE | 80% |
| Sunday | 68°F | Showers And Thunderstorms | 10 to 15 mph NNE | 80% |
| Sunday Night | 55°F | Rain Showers Likely | 15 mph ENE | 59% |
| Monday | 64°F | Chance Rain Showers | 15 mph ENE | 48% |
| Monday Night | 51°F | Chance Rain Showers | 10 to 15 mph ENE | 32% |
| Tuesday | 63°F | Slight Chance Rain Showers | 10 to 15 mph NE | 22% |
| Tuesday Night | 51°F | Mostly Cloudy | 5 to 10 mph NE | 14% |
| Wednesday | 65°F | Partly Sunny | 5 to 10 mph NNE | 8% |
| Wednesday Night | 51°F | Mostly Cloudy | 5 to 10 mph NNE | 4% |
| Thursday | 68°F | Partly Sunny | 5 to 10 mph NNE | 4% |
| Thursday Night | 52°F | Partly Cloudy | 5 mph NNE | 3% |
| Friday | 70°F | Mostly Sunny | 5 mph NNE | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Charles, IL
Last spring frost
Apr 25
First fall frost
Oct 19
Growing season
174 days
Hardiness zone
5b
Explore more for St. Charles, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, West Chicago Dupage Ap, Il (2.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.