Saint Joseph, in Illinois, United States, is home to roughly 4,000 people in the Central Time Zone at 40.1°N latitude.
In 2025, Saint Joseph recorded an average annual temperature of 54°F — about 1.1°F above the 30-year normal of 53°F. The hottest day reached 93°F in July; the coldest was -5°F in December. Total precipitation was 29 inches (drier than usual). The wettest month was April.
View current conditions and forecast for Saint Joseph · More cities in Illinois