St. Charles, MO has a humid continental climate with hot and humid summers and cold, snowy winters. During the summer months, temperatures average in the mid-80s Fahrenheit (29-30°C) with high humidity levels that can make it seem much hotter than it actually is. In winter, temperatures range from just above freezing to as low as 10 degrees Fahrenheit (-11°C). The city also experiences snowfall throughout the winter season, with an average of 17 inches (43cm) of snow per year.
St. Charles, Missouri gets 42 inches of rain, on average, per year. The US average is 38 inches of rain per year.
St. Charles averages 14 inches of snow per year. The US average is 28 inches of snow per year.
On average, there are 202 sunny days per year in St. Charles. The US average is 205 sunny days.
St. Charles gets some kind of precipitation, on average, 106 days per year. Precipitation is rain, snow, sleet, or hail that falls to the ground. In order for precipitation to be counted you have to get at least .01 inches on the ground to measure.
Summer High: the July high is around 88 degrees
Winter Low: the January low is 21
Rain: averages 42 inches of rain a year
Snow: averages 14 inches of snow a year