St. Charles, IL Weather & Growing Conditions
Overnight
59°F
Rain Showers
Rain showers. Cloudy. Low around 59, with temperatures rising to around 62 overnight. South wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 59°F | Rain Showers | 15 mph S | 83% |
| Wednesday | 63°F | Chance Rain Showers then Mostly Cloudy | 15 mph SSW | 26% |
| Wednesday Night | 46°F | Cloudy | 15 mph SW | 13% |
| Thursday | 55°F | Chance Rain Showers | 10 to 15 mph WSW | 47% |
| Thursday Night | 40°F | Chance Rain Showers | 10 mph NW | 48% |
| Friday | 50°F | Partly Sunny | 10 to 15 mph NNW | 12% |
| Friday Night | 33°F | Partly Cloudy | 5 to 10 mph NNW | 0% |
| Saturday | 51°F | Mostly Sunny | 5 mph NW | 0% |
| Saturday Night | 33°F | Mostly Clear | 5 mph W | 0% |
| Sunday | 55°F | Sunny | 5 to 10 mph W | 6% |
| Sunday Night | 34°F | Mostly Clear | 0 to 5 mph W | 0% |
| Monday | 60°F | Sunny | 0 to 10 mph SW | 0% |
| Monday Night | 39°F | Mostly Clear | 5 to 10 mph WSW | 1% |
| Tuesday | 61°F | Sunny | 5 mph WNW | 0% |
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 Nov 4, 2026.