About La Harpe, IL

La Harpe is a city of approximately 1,200 people in Illinois, United States. Located in the Central Time Zone at 40.6°N latitude.

In 2025, La Harpe averaged an annual temperature of 54°F, with hottest temperatures reaching 97°F in May and lowest around -8°F in January. The city received approximately 29 inches of precipitation during the year.