In the town, the population was spread out with 18.3% under the age of 18, 4.2% from 18 to 24, 22.1% from 25 to 44, 25.8% from 45 to 64, and 29.6% who were 65 years of age or older.
The town of Harwich contains several smaller census-designated places (CDPs) for which the U.S. Census reports more focused geographic and demographic information.