Monongahela is a very small city located in the state of Pennsylvania. With a population of 4,108 people and four associated neighborhoods, Monongahela is the 376th largest community in Pennsylvania. Much of the housing stock in Monongahela was built prior to World War II, making it one of the older and more historic cities in the country.

A relatively large number of people in Monongahela telecommute to their jobs. Overall, about 7.31% of the workforce works from home. While this may seem like a small number, as a fraction of the total workforce it ranks among the highest in the country. These workers are often telecommuters who work in knowledge-based, white-collar professions. For example, Silicon Valley has large numbers of people who telecommute. Other at-home workers may be self-employed people who operate small businesses out of their homes.

The education level of Monongahela citizens, measured as those with bachelor's degrees or advanced degrees, is similar to the national average for all American cities and towns. 19.57% of adults 25 and older in Monongahela have a college degree.

The per capita income in Monongahela in 2018 was $30,490, which is lower middle income relative to Pennsylvania, and middle income relative to the rest of the US. This equates to an annual income of $121,960 for a family of four. However, Monongahela contains both very wealthy and poor people as well.

The people who call Monongahela home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of Monongahela residents report their race to be White, followed by Black or African-American. Important ancestries of people in Monongahela include German, Italian, Irish, English, and Polish.

The most common language spoken in Monongahela is English. Other important languages spoken here include Slavic languages and Spanish.