Allerton, Illinois is a small village located in eastern Piatt County. The climate of the area is characterized by warm summers and cold winters, with an average annual temperature of 52°F. The hydrology constituents of Allerton are largely influenced by the Sangamon River, which runs along the eastern border of the village. Outdoor recreation opportunities in Allerton are plentiful, with the 14,000-acre Robert Allerton Park serving as the main attraction. The park offers extensive trails for hiking, birdwatching, and nature study, as well as opportunities for fishing and picnicking. Visitors can also enjoy the park's formal gardens, sculptures, and historic mansion.