Mexicali is the capital city of the Mexican state of Baja California. The city, which is the seat of the Mexicali Municipality, has a population of 689…Mexicali is the capital city of the Mexican state of Baja California. The city, which is the seat of the Mexicali Municipality, has a population of 689,775, according to the 2010 census, while the Calexico–Mexicali metropolitan area is home to 1,000,000 inhabitants on both sides of the Mexico–United States border. Mexicali is a regional economic and cultural hub for the border region of The Californias.