The U.S. Census Bureau released total populations estimates as of July 1, 2024 at the county level. Population estimates are calculated using administrative records to estimate components of population change, such as births, deaths, and migration. The Pennsylvania Data Center released a brief analyzing Pennsylvania’s data. 

Pennsylvania experienced an overall population increase of just over 75,800 (.6%) between 2020 and 2024. Pike County (+6.5%) was the fastest growing county in Pennsylvania followed by Cumberland County (+6.2%). Five other counties grew by 3% or more: Chester (+4.9%), Adams (+3.9%), York (+3.2%), Northampton (+3.2%), and Lehigh (+3.-%).  

The largest county with the largest numeric growth took place in Chester County (+26,327). Seven other counties added at least 10,000 individuals since 2020, including Montgomery (+22,777), Cumberland (+16,048), York (+14,791), Lehigh (+11,103), Lancaster (+10,312), Berks (+10,267), and Northampton (+10,032). 

Between 2020 and 2024, only two counties lost more than 10,000 individuals, Philadelphia (-29,878) and Allegheny (-18,769). Four other counties had losses of 3,000 to 5,000: Fayette (-4,882), Westmoreland (-3,713), and Cambria (-3,355). The largest percentage declines were in Greene (-5.5%), Forest (5.4%), and Cameron (-4.4%). 

Statewide, population growth in Pennsylvania was due to a net growth in migration, led by a gain of 200,000 international migrants, as nearly 50,000 Pennsylvanians left the state during 2020-2024. Deaths outpaced births statewide for a natural decrease of approximately 77,550. Births only outpaced deaths in Philadelphia, Lancaster, Chester, Delaware, Dauphin, Montgomery, Lehigh, and Berks Counties. Click here to read the research brief.