Boundary Atlas

ZIP code 80503: Longmont, CO

ZIP code 80503 is in Longmont (71% of residents), Niwot (12%) and Gunbarrel (2.2%), in Boulder County (100%) and Larimer County (0.1%), Colorado. 15% of its residents live outside city limits. It is in Colorado's 2nd congressional district. Its state senate districts are State Senate District 17 (72%), State Senate District 18 (14%) and State Senate District 15 (14%); its state house districts are State House District 11 (73%), State House District 12 (18%) and State House District 49 (8.9%).

35,863residents (2020 Census)
91.7 sq miland area
4cities and towns
1congressional district
27voting precincts

See it on the mapAll of Colorado

City and county

City or townShare of ZIP residents
Longmont71%
Niwot12%
Gunbarrel2.2%
Lyons<0.1%

CountyShare of ZIP residents
Boulder County100%
Larimer County0.1%

Town or county subdivisionShare of ZIP residents
Longmont CCD96%
Boulder CCD4.3%
Berthoud CCD<0.1%
Loveland CCD<0.1%

Congressional district

Congressional districtShare of ZIP residents
Colorado's 2nd congressional district (CO-02)100%

Elected officials

OfficeMemberContactShare of residents
MayorSusie Hidalgo-Fahring303-651-860171%
U.S. Representative (CO-02)Joe Neguse (D)202-225-2161100%
U.S. SenatorJohn W. Hickenlooper (D)202-224-5941 · contact formstatewide
U.S. SenatorMichael F. Bennet (D)202-224-5852 · contact formstatewide
State Senator (State Senate District 17)Katie Wallace (Democratic)72%
State Senator (State Senate District 18)Judy Amabile (Democratic)14%
State Senator (State Senate District 15)Janice Marchman (Democratic)14%
State Representative (State House District 11)Karen McCormick (Democratic)73%
State Representative (State House District 12)Kyle Brown (Democratic)18%
State Representative (State House District 49)Lesley Smith (Democratic)8.9%
State Representative (State House District 10)Junie Joseph (Democratic)<0.1%

Officials serving now (members of Congress until January 3, 2027). Sources: Mayors: Open States (public domain); State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).

Local government

State legislative districts

State senate districtShare of ZIP residents
State Senate District 1772%
State Senate District 1814%
State Senate District 1514%

State house districtShare of ZIP residents
State House District 1173%
State House District 1218%
State House District 498.9%
State House District 10land only

Voting precincts

27 voting precincts overlap ZIP 80503. Map them, with each precinct's share of the ZIP's residents.

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ZIP 80503 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.