3rd federal electoral district of Sonora

Under the 2023 districting plan adopted by the National Electoral Institute (INE), which is to be used for the 2024, 2027 and 2030 federal elections,^[7] Sonora's 3rd district covers 200 electoral precincts (secciones electorales) across the north-western half of the municipality of Hermosillo, including Tiburón Island.^[8][9]

The head town (cabecera distrital), where results from individual polling stations are gathered together and tallied, is the state capital, the city of Hermosillo. The district reported a population of 467,597 in the 2020 Census.^[1]

2017–2022

Between 2017 and 2022, the district covered the north-western half of the municipality of Hermosillo, similar to the 2023 scheme.^[12][13]

2005–2017

Under the 2005 plan, the district covered a north-western portion of the municipality of Hermosillo, with its head town in the state capital.^[14][15]

1996–2005

Under the 1996 districting plan, the head town was at Hermosillo and the district covered the northern half of the municipality.^[16][15]

1978–1996

The districting scheme in force from 1978 to 1996 was the result of the 1977 electoral reforms, which increased the number of single-member seats in the Chamber of Deputies from 196 to 300. Under that plan, Sonora's seat allocation rose from four to seven.^[10] The 3rd district had its head town at Guaymas and it covered the municipalities of Bácum, Guaymas and Empalme.^[17]