The San Francisco Peaks are subject to a wide range of climate conditions. Precipitation ranges from 20 inches in the lower area of the mountain to over 40 inches on the upper slopes. Temperatures fluctuate greatly from night to day. Travelers must be prepared for inclement weather conditions. Rainproof outer garments and waterproof shelters should be included with equipment. Pacific cold fronts, with accompanying rain or snow, can move in very quickly. May and June are drier periods, while July and August are usually periods of violent thunderstorms and monsoons. Precautions should be taken to avoid being caught on exposed peaks and ridge tops during such storms. Plan ahead; watch approaching storms and get to a safe area before the storms hit. A forested area away from ridge tops, ledges or rock outcroppings and the tallest trees are the safest places to be.
Several factors make it necessary to implement some restrictions — the fragile habitat of the Peaks, a threatened plant species, the Kachina Peaks Wilderness designation, and the municipal watershed for the City of Flagstaff in the Inner Basin.
Endangered species are located above timberline; therefore, hiking is restricted to designated trails only.