<P> This is a list of the fifty most populous metropolitan areas in the Americas as of 2015, the most recent year for which official census results, estimates or projections are available for every major metropolitan area in the Americas . Where available, it uses official definitions of metropolitan areas based on the concept of a single urban core and its immediate surroundings, as opposed to polycentric conurbations . Figures refer to mid-2015 populations except in the case of Mexican metropolitan areas, whose figures derive from the 2015 Intercensal Survey conducted by INEGI with a reference date of 15 March 2015 . </P> <Table> <Tr> <Th> </Th> <Th> Metropolitan area </Th> <Th> Population </Th> <Th> Year </Th> <Th> Country </Th> </Tr> <Tr> <Td> </Td> <Td> São Paulo </Td> <Td> 21,090,792 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> </Td> <Td> Mexico City </Td> <Td> 20,892,724 </Td> <Td> 2015 </Td> <Td> Mexico </Td> </Tr> <Tr> <Td> </Td> <Td> New York </Td> <Td> 20,182,305 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> </Td> <Td> Buenos Aires </Td> <Td> 13,693,657 </Td> <Td> 2015 </Td> <Td> Argentina </Td> </Tr> <Tr> <Td> </Td> <Td> Los Angeles </Td> <Td> 13,340,068 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Rio de Janeiro </Td> <Td> 12,280,702 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Lima </Td> <Td> 9,904,727 </Td> <Td> 2015 </Td> <Td> Peru </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Chicago </Td> <Td> 9,551,031 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Bogotá </Td> <Td> 9,286,225 </Td> <Td> 2015 </Td> <Td> Colombia </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Dallas--Fort Worth </Td> <Td> 7,102,796 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 11 </Td> <Td> Santiago </Td> <Td> 6,683,852 </Td> <Td> 2015 </Td> <Td> Chile </Td> </Tr> <Tr> <Td> 12 </Td> <Td> Houston </Td> <Td> 6,656,947 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 13 </Td> <Td> Toronto </Td> <Td> 6,129,934 </Td> <Td> 2015 </Td> <Td> Canada </Td> </Tr> <Tr> <Td> 14 </Td> <Td> Washington </Td> <Td> 6,097,684 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 15 </Td> <Td> Philadelphia </Td> <Td> 6,069,875 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 16 </Td> <Td> Miami </Td> <Td> 6,012,331 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 17 </Td> <Td> Belo Horizonte </Td> <Td> 5,829,923 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 18 </Td> <Td> Atlanta </Td> <Td> 5,710,795 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 19 </Td> <Td> Caracas </Td> <Td> 5,322,310 </Td> <Td> 2015 </Td> <Td> Venezuela </Td> </Tr> <Tr> <Td> 20 </Td> <Td> Guadalajara </Td> <Td> 4,796,603 </Td> <Td> 2015 </Td> <Td> Mexico </Td> </Tr> <Tr> <Td> 21 </Td> <Td> Boston </Td> <Td> 4,774,321 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 22 </Td> <Td> San Francisco--Oakland </Td> <Td> 4,656,132 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 23 </Td> <Td> Phoenix </Td> <Td> 4,574,531 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 24 </Td> <Td> Riverside--San Bernardino </Td> <Td> 4,489,159 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 25 </Td> <Td> Monterrey </Td> <Td> 4,475,949 </Td> <Td> 2015 </Td> <Td> Mexico </Td> </Tr> <Tr> <Td> 26 </Td> <Td> Detroit </Td> <Td> 4,302,043 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 27 </Td> <Td> Porto Alegre </Td> <Td> 4,258,926 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 28 </Td> <Td> Brasília </Td> <Td> 4,201,737 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 29 </Td> <Td> Montreal </Td> <Td> 4,060,692 </Td> <Td> 2015 </Td> <Td> Canada </Td> </Tr> <Tr> <Td> 30 </Td> <Td> Fortaleza </Td> <Td> 3,985,297 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 31 </Td> <Td> Salvador </Td> <Td> 3,953,290 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 32 </Td> <Td> Recife </Td> <Td> 3,914,397 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 33 </Td> <Td> Medellín </Td> <Td> 3,777,009 </Td> <Td> 2015 </Td> <Td> Colombia </Td> </Tr> <Tr> <Td> 34 </Td> <Td> Seattle </Td> <Td> 3,733,580 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 35 </Td> <Td> Santo Domingo </Td> <Td> 3,658,648 </Td> <Td> 2015 </Td> <Td> Dominican Republic </Td> </Tr> <Tr> <Td> 36 </Td> <Td> Minneapolis--St. Paul </Td> <Td> 3,524,583 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 37 </Td> <Td> Curitiba </Td> <Td> 3,502,804 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 38 </Td> <Td> San Diego </Td> <Td> 3,299,521 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 39 </Td> <Td> Campinas </Td> <Td> 3,094,181 </Td> <Td> 2015 </Td> <Td> Brazil </Td> </Tr> <Tr> <Td> 40 </Td> <Td> Tampa--St. Petersburg </Td> <Td> 2,975,225 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 41 </Td> <Td> Guayaquil </Td> <Td> 2,952,159 </Td> <Td> 2015 </Td> <Td> Ecuador </Td> </Tr> <Tr> <Td> 42 </Td> <Td> Puebla--Tlaxcala </Td> <Td> 2,941,988 </Td> <Td> 2015 </Td> <Td> Mexico </Td> </Tr> <Tr> <Td> 43 </Td> <Td> Cali </Td> <Td> 2,911,278 </Td> <Td> 2015 </Td> <Td> Colombia </Td> </Tr> <Tr> <Td> 44 </Td> <Td> Denver </Td> <Td> 2,814,330 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 45 </Td> <Td> St. Louis </Td> <Td> 2,811,588 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 46 </Td> <Td> Baltimore </Td> <Td> 2,797,407 </Td> <Td> 2015 </Td> <Td> United States </Td> </Tr> <Tr> <Td> 47 </Td> <Td> Guatemala City </Td> <Td> 2,749,161 </Td> <Td> 2015 </Td> <Td> Guatemala </Td> </Tr> <Tr> <Td> 48 </Td> <Td> Quito </Td> <Td> 2,653,330 </Td> <Td> 2015 </Td> <Td> Ecuador </Td> </Tr> <Tr> <Td> 49 </Td> <Td> Port - au - Prince </Td> <Td> 2,618,894 </Td> <Td> 2015 </Td> <Td> Haiti </Td> </Tr> <Tr> <Td> 50 </Td> <Td> Maracaibo </Td> <Td> 2,576,836 </Td> <Td> 2015 </Td> <Td> Venezuela </Td> </Tr> </Table>

What is the largest metropolitan area in the western hemisphere