Monongahela City, Washington County, Pennsylvania
| Monongahela | |
| City | |
 Edward G. Acheson House in 2011
| |
| Official name: City of Monongahela | |
| Named for: Monongahela River | |
| Nickname: Mon City | |
| Country | United States |
|---|---|
| State | Pennsylvania |
| County | Washington |
| Area | 2.1 sq mi (5 km2) |
| - land | 1.9 sq mi (5 km2) |
| - water | 0.2 sq mi (1 km2) |
| Population | 4,300 (2010) |
| Density | 2,263.2 / sq mi (874 / km2) |
| Established | 1770 |
| Mayor | Bob Kepics (D) |
| Timezone | EST (UTC-4) |
| - summer (DST) | EDT (UTC-5) |
| ZIP code | 15063 |
| Area code | 724 |
 Location of Monongahela within Pennsylvania
| |
 Location of Pennsylvania in the United States
| |
| Website: www.cityofmonongahela-pa.gov | |