Mount Washington Weather: The 231 mph Wind and the World's Worst Weather

Mount Washington in New Hampshire is only 6,288 ft (1,917 m) high, yet its summit has some of the most violent weather on Earth. In April 1934 observers here measured a gust of 231 mph (372 km/h), and in winter the summit buildings disappear under thick coats of rime ice. The mountain's famous nickname, "Home of the World's Worst Weather", is earned every year.

Why Mount Washington's weather is so extreme

Mount Washington is the highest peak in the northeastern United States and the most prominent mountain east of the Mississippi. It rises in the Presidential Range of the White Mountains, and three things make its weather so wild.

• Storm tracks. Several major storm tracks converge over New England, so the summit is hit by systems from the west, the south and the Atlantic coast.
• Funnelling. The Presidential Range runs roughly north to south, across the prevailing westerly winds. Air is forced up and over the ridge and speeds up as it squeezes across the top.
• Height in a cold, wet airmass. The summit sits in cloud much of the year, and supercooled fog droplets freeze on contact with anything solid, building rime ice that grows into the wind.

The numbers show the result. The summit records hurricane-force gusts on about 110 days a year, receives roughly 280 inches (7.1 m) of snow in an average season and has an annual mean temperature of about −2 °C (28 °F). The record low is −50 °F (−46 °C), set on 22 January 1885.

The 231 mph "Big Wind" of 1934

The Mount Washington Observatory was founded in 1932 as a private, non-profit weather station staffed through the winter. On 12 April 1934, during a fierce storm with heavy icing, its heated anemometer recorded a gust of 231 mph. Observer Sal Pagliuca was on duty, and the reading was checked thoroughly before it was accepted.

It stood as the highest wind ever measured on Earth for 62 years, until Tropical Cyclone Olivia produced a gust of 253 mph (408 km/h) on Barrow Island, Australia, in April 1996, recorded by an automatic station. Mount Washington's 231 mph remains the fastest wind ever recorded at a staffed weather station. The original Heated No. 2 anemometer is on display in the summit museum.

The observatory and its ice-covered summit

Observers still live on the summit year-round, working in week-long shifts and climbing the instrument tower in storms to knock rime off the sensors by hand. No commercial instrument survives a Mount Washington winter, so the observatory designs its own heated pitot anemometers. Its records, kept since 1932, are among the longest continuous mountain weather series in North America.

The rime grows as feathers pointing into the wind, sometimes several feet long after a single storm, and turns railings, signs and rocks into white sculptures.

History on the summit: chained buildings and the Tip-Top House

People have built on this summit since the 1850s, and the wind taught them to hold on. The first Summit House, opened in 1852, was anchored with heavy chains over its roof, and other buildings were chained to the mountain too. The stone Tip-Top House of 1853 is the oldest surviving building on the summit; it was the only one to survive the fire of 1908 and is now part of Mount Washington State Park.

How to visit Mount Washington

There are three classic ways to the top. The Mount Washington Cog Railway, running since 1869 and the world's first mountain-climbing cog railway, climbs the western slope. The 7.6-mile (12.2 km) Mount Washington Auto Road, opened in 1861, winds up the east side from Pinkham Notch. Hikers most often take the Tuckerman Ravine Trail, 4.1 miles (6.6 km) with 4,280 ft (1,300 m) of climbing, and the Appalachian Trail crosses the summit.

In summer the summit has the Sherman Adams visitor centre, a café and the observatory's Extreme Mount Washington museum. Check the observatory's higher-summits forecast before you go: even in July the summit can be in freezing fog with gale-force winds, and more than 160 people have died in the Presidential Range since 1849. Carry warm layers whatever the valley weather looks like.

Related reading

• Ten Historic Winter-Weather Episodes in the United States
• Historic Freeze Could Break Midwest Temp Records
• Edge of Stability: Jeff Boyce’s Storm and Night-Sky Film
• Tioga Road and Tioga Pass: Yosemite’s High-Country Drive
• Olympic National Park: Mountains, Rain Forest and Pacific Coast
• American Loneliness: Mathieu Le Lay’s Journey Through the West

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