Mexicali is one of the hottest cities in Mexico. Summer temperatures regularly exceed 45°C (113°F), and the early-afternoon heat between June and September makes daytime sightseeing genuinely uncomfortable. Locals shift their lives to early mornings and late evenings during these months. Air conditioning is universal in restaurants and shops; on the street, you will sweat constantly.
The best time to visit is between November and March, when temperatures sit in the comfortable 15–25°C range and the desert nights are cool. The annual Fiestas del Sol fair in October draws people from across the region. February and March are particularly pleasant. Rain is rare — Mexicali sits in a true desert and receives only about 75 mm of precipitation a year, mostly in winter.