Blain, PA has a population of 284 and is the 22,771st largest city in the United States. The population density is 894 per sq mi which is 223% higher than the Pennsylvania average and 887% higher than the national average. The median age in Blain is 31 which is approximately 23% lower than the Pennsylvania average of 41. In Blain, 54% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 86% of Blain residents were born in Pennsylvania, 14% were born out of state, 0% were born outside of the United States and 0% were foreign born.