In 2022, the population of Blain was 224, a 0.44% decrease year-by-year from 2021. Previously, in 2021, Blain's population was 225, an increase of 0.90% compared to a population of 223 in 2020.
The median age in Blain, PA is 36.4, as per 2021 ACS 5-Year Estimates. Of the total population, 25.31% were under the age of 15, 16.60% aged 15 to 29, 42.74% aged 30 to 64, 13.69% aged 65 to 84, and 1.66% were 85 years of age and older.