Occasional snowfalls blanket the canyon.
(NPS photo by David Bly)
Two climatic features, mild annual temperatures and abundant summer precipitation, predominate in Coronado National Memorial and the surrounding area. Maximum average temperatures occur in July (80 degrees F); minimum average monthly temperatures occur in January (46 degrees F). Arizona has two rainy seasons. The summer rainy season occurs in July and August, and the winter rainy season from December to March. During the summer, monsoonal airflow transports moisture from the southern Pacific Ocean and Gulf of California, while during the winter, cyclonic storms originate in the northern Pacific Ocean. The characteristics of summer and winter storms are fundamentally different. Summer precipitation occurs in scattered and localized storms of shorter duration while winter precipitation is characterized by widespread storms of longer duration. At Coronado National Memorial, approximately twice as much precipitation falls in the summer compared to the winter.