Mount Vernon, in Illinois, United States, is home to roughly 15,100 people in the Central Time Zone at 38.3°N latitude.
In 2025, Mount Vernon recorded an average annual temperature of 57°F. The hottest temperatures reached 96°F in July; the coolest were -1°F in January. Total precipitation for the year was 44 inches, with the wettest month being April. Snowfall for the year totaled approximately 7 inches.
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