Saint Charles Weather Forecast
- 77
- 94
Chance Thunderstorms
- 77
- 96
Chance Thunderstorms
- 78
- 96
Slight Chance Thunderstorms
- 79
- 98
Hot
- 79
- 100
Hot
- 77
- 99
Hot
Today 19 Jul St. Charles
Partly sunny with a chance of Showers and Thunderstorms. Humid with Highs in the lower 90s. Southwest Winds 5 to 10 Mph. Chance of rain 50 percent. Heat index Values up to 106.
Tonight 19 Jul St. Charles
A slight chance of Thunderstorms in the evening. Mostly clear with a slight chance of Showers. Humid with Lows in the mid 70s. Southwest Winds around 5 Mph. Chance of rain 20 percent. Heat index Values up to 104 early in the evening.
Saint Charles Temperature Statistics
July Temperature
St. Louis Lambert International Airport (6.2 miles)
Lowest 2 July, 2025
68 °FAverage July
81.3 °FHighest 11 July, 2025
94.6 °F
Climate (2020–Present)
St. Louis Lambert International Airport (6.2 miles)
Average Low 2020–2025
50.3 °FAverage 2020–2025
59.6 °FAverage High 2020–2025
69 °F