Since the Copper Canyon area is made up two different climatic zones from Alpine at the top of the canyons to subtropical at the bottom, visitors should know that different times of the year and different areas of the canyon will offer different weather.
Generally, early fall and late spring have the best temperatures, usually mild around 70F during the day, 60F at night on the rim. The temperatures at the bottom of the canyons can reach 80F-90F at this time of the year. Since the weather is best at this time, it's also the most crowded time in the canyons, so some facilities may be sold out.
Winters (November-March) can be cold, especially at night. Days can be 40F-50F with nights dropping to freezing at times along the rim of the canyon. Snow sometimes will fall at higher elevations, and most storms roll through in December and January. Late February and March brings warmer air to the canyon's upper reaches. At the bottom of the canyon, temperatures are between 60F-70F (nights 50F). There can be occasional rain at the bottom due to the winter snow storms at the top.
Summer brings dry, warm air to the upper reaches with temperatures in the 70F-80F range. The bottom of the canyons can reach 100F and become very humid during May-July period. Summer rainstorms can hit any time from July to September and bring the bottom canyon temperatures down. Some larger storms have taken out dirt roads and small bridges with flooding.
The capital, Chihuahua, is high desert and the temperature can range from cold winter days and nights, to dry, hot summer days. Los Mochis and El Fuerte sit along the coastal plain of the Sea of Cortez. They can be very mild in the winters, warm in the spring and fall, and hot and humid in the summer.