Mercer County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 110,652. Its county seat is Mercer, and its largest city is Hermitage. The county is part of the Northwest Pennsylvania region of the state.
Mercer County compromises the Hermitage, PA Micropolitan Statistical Area, which is included in the Greater Pittsburgh area.
History
Mercer County was created in 1800 and later organized in 1803.
Geography
According to the U.S. Census Bureau, the county has a total area of , of which is land and (1.5%) is water. It has a humid continental climate (Dfa/Dfb) and average monthly temperatures in Sharon range from 27.1 °F in January to 72.2 °F in July, while in Mercer borough they range from 25.4 °F in January to 70.1 °F in July. Mercer County is one of the 423 counties served by the Appalachian Regional Commission, and it is identified as part of the "Midlands" by Colin Woodard in his book American Nations: A History of the Eleven Rival Regional Cultures of North America.
Adjacent counties
- Crawford County (north)
- Venango County (east)
- Butler County (southeast)
- Lawrence County (south)
- Mahoning County, Ohio (southwest)
- Trumbull County, Ohio (west)