17. Mount Washington, USA
Mount Washington in New Hampshire is notorious for its unpredictable and often violent weather. This peak once held the world record for the fastest surface wind speed—an astonishing 231 mph (372 km/h). Sudden storms, freezing fog, and rapid temperature drops make conditions treacherous throughout the year. Hypothermia and frostbite are constant threats to those who underestimate the mountain’s power. Even experienced hikers can be caught off guard by the rapidly changing conditions.