The city and its surrounding area has a population of nearly 700,000 people. Its economy is a mixture of industry and agriculture. It is the national aerospace center for Mexico. It is situated on the border, with its sister city of Calexico situated in the U.S.
Not much is known about Mexicali after the onset of the apocalypse. It can be inferred that, similar to Tijuana and the rest of Baja California, large sections of it are swarming with the Infected. It was mentioned in the episode The Diviner that there is a trading post in the city, so some survivors and infrastructure survive.
The trading post is revealed to be located at El Bazar, literally 'The Bazaar', and is situated within an old bullfighting arena.