Boundary Atlas

ZIP code 01077: Southwick, MA

ZIP code 01077 is in Hampden County, Massachusetts, outside any city or Census-designated place. It is in Massachusetts's 1st congressional district. Its state senate districts are Berkshire-Hampden-Franklin-Hampshire District (100%) and Hampden and Hampshire District (<0.1%); its state house districts are 3rd Hampden District (100%) and 4th Hampden District (<0.1%).

9,237residents (2020 Census)
30.9 sq miland area
1cities and towns
1congressional district
4voting precincts

See it on the mapAll of Massachusetts

City and county

City or townShare of ZIP residents
Westfield<0.1%

CountyShare of ZIP residents
Hampden County100%

Town or county subdivisionShare of ZIP residents
Southwick town100%
Westfield city<0.1%

Congressional district

Congressional districtShare of ZIP residents
Massachusetts's 1st congressional district (MA-01)100%

State legislative districts

State senate districtShare of ZIP residents
Berkshire-Hampden-Franklin-Hampshire District100%
Hampden and Hampshire District<0.1%

State house districtShare of ZIP residents
3rd Hampden District100%
4th Hampden District<0.1%

Voting precincts

4 voting precincts overlap ZIP 01077. Map them, with each precinct's share of the ZIP's residents.

Get this in your AI agent

Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:01077")

ZIP 01077 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.