Yes, Mount Fuji is significantly colder than Tokyo throughout the entire year due to its extreme altitude. While Tokyo sits at sea level, the summit of Mt. Fuji reaches 3,776 meters (12,389 feet). On average, temperature drops by about 0.6∘C for every 100 meters of elevation. This means the summit is typically 20 to 25 degrees Celsius colder than the streets of Shinjuku. In the peak of summer (July/August), when Tokyo is sweltering at a humid 32∘C (90∘F), the temperature at the summit of Mt. Fuji often hovers between 5∘C and 10∘C (41∘F–50∘F), and can even drop below freezing at night. In the winter, while Tokyo rarely sees snow, the mountain is encased in ice with temperatures plunging to −20∘C or lower, accompanied by hurricane-force winds. For 2026 hikers, this means that even if you leave Tokyo in a T-shirt and shorts, you must carry heavy winter gear, including windbreakers and thermal layers, to survive the conditions at the top, as hypothermia is a real risk even in the middle of the summer climbing season.