Mount Washington is an ultra-prominent mountain in the state of New Hampshire. It is the highest peak in the Northeastern United States at 6,288.2 ft and the most topographically prominent mountain east of the Mississippi River. The mountain is notorious for its erratic weather. On the afternoon of April 12, 1934, the Mount Washington Observatory recorded a windspeed of 231 miles per hour at the summit, the world record from 1934 until 1996.