About Sleepy Hollow, IL's Climate & Weather History

With a population of around 3,300, Sleepy Hollow sits in Illinois, United States. The city operates in the Central Time Zone.

In 2025, Sleepy Hollow recorded an average annual temperature of 50°F — about 0.9°F below the 30-year normal of 51°F. The hottest day reached 93°F in May; the coldest was -11°F in February. Total precipitation was 33 inches (near normal). The wettest month was July.