Hainesville is a city of approximately 3,700 people in Illinois, United States. Located in the Central Time Zone at 42.3°N latitude.
In 2025, Hainesville recorded an average annual temperature of 50°F — about 1.2°F above the 30-year normal of 48°F. The hottest day reached 94°F in July; the coldest was -10°F in February. Total precipitation was 33 inches (drier than usual). The wettest month was July.
View current conditions and forecast for Hainesville · More cities in Illinois