St. Charles, IL Weather & Growing Conditions
Overnight
63°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 4am, then showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy. Low around 63, with temperatures rising to around 65 overnight. East southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 63°F | Chance Showers And Thunderstorms | 10 mph ESE | 90% |
| Saturday | 77°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 100% |
| Saturday Night | 63°F | Showers And Thunderstorms | 5 to 10 mph E | 96% |
| Sunday | 69°F | Showers And Thunderstorms Likely | 10 to 15 mph NNE | 60% |
| Sunday Night | 55°F | Chance Rain Showers | 15 mph NE | 29% |
| Monday | 64°F | Chance Rain Showers | 15 mph ENE | 33% |
| Monday Night | 51°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 22% |
| Tuesday | 62°F | Slight Chance Rain Showers | 10 to 15 mph NE | 16% |
| Tuesday Night | 51°F | Mostly Cloudy | 10 to 15 mph NE | 8% |
| Wednesday | 65°F | Partly Sunny | 10 to 15 mph NE | 9% |
| Wednesday Night | 52°F | Mostly Cloudy | 5 to 10 mph NNE | 3% |
| Thursday | 67°F | Partly Sunny | 5 to 10 mph NNE | 3% |
| Thursday Night | 52°F | Mostly Cloudy | 5 mph NNE | 3% |
| Friday | 71°F | Mostly Sunny | 5 to 10 mph NE | 4% |
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.