There are 89 US Post Offices in Middlesex County serving a total of 1,753,095 residents equating to 19,698 residents per post office. It's estimated that approximately 2,798,135 packages are handled across the 89 county post offices annually. Middlesex County is a county in the Commonwealth of Massachusetts, in the United States. As of 2014, the estimated population was 1,570,315, making it the twenty-third most populous county in the United States, and the most populous county in both Massachusetts and New England. For administrative purposes the county held two regions, Middlesex-North with its county seat in Lowell, and Middlesex-South with its county seat in Cambridge. Middlesex County is included in the Boston-Cambridge-Newton, MA-NH Metropolitan Statistical Area. The county government was abolished in 1997, but the county boundaries continue to describe a state district for court jurisdictions and for other administrative purposes, such as an indicator for elections. Massachusetts counties also define locations for National Weather Service weather alerts (such as severe thunderstorm warnings). In 2010, the center of population of Massachusetts was located in Middlesex County, in the town of Natick."