St Charles Weather Forecast
- 71
- 86
Chance Thunderstorms
- 75
- 87
Chance Thunderstorms
- 77
- 93
Chance Thunderstorms
- 76
- 94
Chance Thunderstorms
- 78
- 95
Slight Chance Thunderstorms
- 78
- 98
Hot
Today 17 Jul St. Charles
Partly sunny. A slight chance of Showers and Thunderstorms in the Morning, then a chance of Showers and Thunderstorms in the afternoon. Humid with Highs in the upper 80s. North Winds around 5 Mph. Chance of rain 50 percent. Heat index Values up to 100.
Tonight 17 Jul St. Charles
Mostly cloudy with a chance of Showers and Thunderstorms. Lows in the lower 70s. Northeast Winds around 5 Mph. Chance of rain 50 percent.
St Charles Temperature Statistics
July Temperature
St. Louis Lambert International Airport (7.5 miles)
Lowest 2 July, 2025
68 °FAverage July
81.2 °FHighest 11 July, 2025
94.6 °F
Climate (2020–Present)
St. Louis Lambert International Airport (7.5 miles)
Average Low 2020–2025
50.3 °FAverage 2020–2025
59.6 °FAverage High 2020–2025
69 °F