The coldest day ever recorded in Mount Vernon, IL, was on February 10, 1899, when the temperature plummeted to a frigid -22°F (-30°C). This record-breaking temperature was part of a particularly harsh winter during that time period, which saw unusually heavy snowfall and low temperatures throughout the region. So, if you think it’s cold in Mount Vernon today, just remember that it could be worse!
At the other end of the spectrum, the warmest day ever recorded in Mount Vernon, IL, was on July 14, 1936, when the temperature soared to a sweltering 114°F (45.6°C). This record-breaking heatwave was a stark contrast to the frigid temperatures experienced in 1899, demonstrating the wide range of weather extremes that can occur in the region.
These days, the average temperature in Mount Vernon, IL, typically ranges from 24°F (-4.4°C) in the winter months to 88°F (31.1°C) during the summer. These temperature extremes are rare, though, and you can generally expect milder weather throughout the year. The average temperature across all seasons is around 54°F (12.2°C), making Mount Vernon a pleasant place to live or visit for those who prefer moderate climates. With this said, generally the average temperature in Mt. Vernon is pretty typical when compared to the US in general and the midwest region.