Boundary Atlas

ZIP code 95403: Santa Rosa, CA

ZIP code 95403 is in Santa Rosa (76% of residents), Larkfield-Wikiup (18%) and Windsor (1.0%), in Sonoma County, California. It is in California's 1st congressional district. Its state senate district is State Senate District 2; its state house district is Assembly District 2.

44,705residents (2020 Census)
21.5 sq miland area
4cities and towns
1congressional district
36voting precincts

See it on the mapAll of California

City and county

City or townShare of ZIP residents
Santa Rosa76%
Larkfield-Wikiup18%
Windsor1.0%
Fulton<0.1%

CountyShare of ZIP residents
Sonoma County100%

Town or county subdivisionShare of ZIP residents
Santa Rosa CCD99%
Healdsburg CCD1.4%

Congressional district

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

State legislative districts

State senate districtShare of ZIP residents
State Senate District 2100%

State house districtShare of ZIP residents
Assembly District 2100%

Voting precincts

36 voting precincts overlap ZIP 95403. 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:95403")

ZIP 95403 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.