Diadema (Portuguese pronunciation: [dʒi.ɐˈdemɐ], uncommonly [dʒɐˈdemɐ]) is a municipality in São Paulo state, Brazil. Belonging to the ABCD Region of Greater São Paulo, it is 17 km (11 mi) distant from São Paulo's central point. Initially part of São Bernardo do Campo, Diadema became a city of its own in 1959. The population is 412,428 (2015 est.) in an area of 30.76 km2 (11.88 sq mi). The annual mean temperature in the city is 19.6 °C (67.3 °F). Its HDI is 0.790.