St. Charles, IL Weather & Growing Conditions
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. South southwest wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 10 mph SSW | 0% |
| Tonight | 67°F | Mostly Cloudy then Chance Showers And Thunderstorms | 5 mph SSW | 39% |
| Wednesday | 79°F | Showers And Thunderstorms Likely | 5 mph SW | 74% |
| Wednesday Night | 63°F | Showers And Thunderstorms | 0 to 5 mph NW | 86% |
| Thursday | 79°F | Rain Showers Likely then Slight Chance Showers And Thunderstorms | 0 to 5 mph E | 61% |
| Thursday Night | 61°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph SSE | 24% |
| Friday | 82°F | Mostly Sunny | 0 to 5 mph S | 6% |
| Friday Night | 63°F | Slight Chance Showers And Thunderstorms | 0 to 5 mph SSW | 15% |
| Saturday | 84°F | Mostly Sunny | 5 to 10 mph SW | 10% |
| Saturday Night | 68°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 19% |
| Sunday | 85°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph SW | 19% |
| Sunday Night | 68°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 41% |
| Monday | 85°F | Chance Showers And Thunderstorms | 5 to 10 mph SSW | 41% |
| Monday Night | 68°F | Chance Showers And Thunderstorms | 5 to 10 mph WSW | 46% |
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 Aug 4, 2026.