Torreón sits in an arid basin at around 1,120 metres elevation, and its climate is essentially desert: hot, dry, and extreme. Summers are genuinely fierce — July and August regularly hit 40°C or above, and the sun at this latitude has real force. Winter nights can drop close to freezing, though daytime temperatures are usually pleasant.
Spring (March–May) and autumn (September–November) are the best times to visit. Temperatures are warm but manageable, the city is at its most livable, and if you are planning a trip out to the Zona del Silencio or other desert excursions, this is when the conditions are most comfortable. October in particular tends to be excellent: warm days, cool nights, and the possibility of wildflowers in the desert after summer rains.
Avoid July and August if you have the choice. The heat is exhausting, outdoor sightseeing becomes unpleasant after about 10am, and the Cristo de las Noas hilltop in particular is punishing at midday. If you must visit in summer, plan your outdoor activities for early morning and retreat indoors for the middle of the day.
There is no major festival that makes Torreón a particularly compelling destination at a specific time of year, though the Mexican Baseball League season (roughly March to August) gives the city an extra pulse of energy on game nights.