Wheaton experiences a humid continental climate (Köppen climate classification *Dfa*), typical of the American Midwest. This means residents experience four distinct seasons with significant temperature variations throughout the year.
Summers are typically hot and humid, with average high temperatures in July reaching around 84°F (29°C). Winters are cold and often snowy, with January lows averaging around 16°F (-9°C). The city receives approximately 39 inches of rain and 30 inches of snow annually.
The best time to visit is during the late spring (May to June) and early autumn (September to October), when the weather is mild and the local foliage is vibrant. Natural disasters are relatively rare but can include severe summer thunderstorms, occasional tornadoes, and heavy winter blizzards.