Mount Washington
Mount Washington from Intervale
Highest point
Elevation	6,288.3 ft (1,916.7 m) NAVD 88[1]
Prominence	6,148 ft (1,874 m)[2]
Listing	U.S. most isolated peaks 6th U.S. most prominent peaks 59th U.S. state high point 18th New England Fifty Finest 1st White Mountain 4000-footers 1st Ultra prominent peak
Coordinates	44°16′13.8″N 71°18′11.7″W / 44.270500°N 71.303250°W / 44.270500; -71.303250[1]
Geography
Location in New Hampshire Show map of New Hampshire Location in the United States Show map of the United States
Location	Sargent's Purchase Coös County New Hampshire, U.S.
Parent range	Presidential Range
Topo map	USGS Mount Washington[3]
Climbing
First ascent	1642 (first recorded)
Easiest route	Hike, ride cog railway, or drive via Mount Washington Auto Road.

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 (1,916.6 m) 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 (372 km/h) at the summit, the world record from 1934 until 1996. Mount Washington still holds the record for highest measured wind speed not associated with a tornado or tropical cyclone.^[4][a]

The mountain is located in the Presidential Range of the White Mountains, in Coös County, New Hampshire. The mountain is in several unincorporated townships, with the summit in the township of Sargent's Purchase. While nearly the whole mountain is in the White Mountain National Forest, an area of 60.3 acres (24.4 ha) surrounding and including the summit is designated as Mount Washington State Park.

The Mount Washington Cog Railway ascends the western slope of the mountain, and the Mount Washington Auto Road climbs to the summit from the east. The mountain is visited by hikers from various approaches,^[6] including the Appalachian Trail, which traverses the summit.^[7] Other common activities include glider flying, backcountry skiing, and annual cycle and running races such as the Auto Road Bicycle Hillclimb and Road Race.

History

Before European settlers arrived in the region, the mountain was known by various indigenous peoples as Kodaak Wadjo ("the top is so hidden" or "summit of the highest mountain") or Agiochook or Agiocochook ("the place of the Great Spirit" or "the place of the Concealed One").^[8] The Algonquians called the summit Waumbik, "white rocks".^[8][9] The Abenaki people inhabiting the region at the time of European contact believed that the tops of mountains were the dwelling place of the gods and did not climb them out of religious deference to their sanctity.^[10]

In 1524, Giovanni da Verrazzano became the first European to mention the mountain. Viewing it from the Atlantic Ocean, he described what he saw as "high interior mountains".^[11]

In 1642, Darby Field claimed to have made the first ascent of Mount Washington.^[12] Field climbed the mountain in June of that year to demonstrate to the Abenaki chief Passaconaway that the Europeans bargaining for tribal land were not subject to the gods believed to inhabit the summit, a primarily political move that facilitated colonists' northern expansion.^[10] Field again summited Agiocochook in October 1642 on an early surveying expedition that created maps of land as far as Maine, which allowed people from the Massachusetts colony to identify arable coastal areas.^[10]

In 1784, a geology party, headed by Manasseh Cutler, named the mountain.^[13]

In 1819, the Crawford Path was established from Crawford Notch to the summit. It is the oldest continuously maintained hiking path in the United States.^[14] Abel Crawford led a group that included several Harvard students on the first recorded ascent of the path on September 10, 1819. Among them were Samuel Joseph May, George B. Emerson, Samuel E. Sewall, Caleb Cushing, Joseph Coolidge, William Ware and Joseph G. Moody.^[15]

On August 31, 1821, Eliza, Harriet, and Abigail Austin, three sisters from Jefferson, New Hampshire, became the first White women to set foot atop Mount Washington. This was likely the first significant mountain to be climbed by any Euro-American females in the United States.^[15]

In 1821, Ethan Allen Crawford built a house on the summit. The house lasted until a storm in 1826.^[13]

Little occurred on the summit itself until the mid-19th century, when it was developed into one of the first tourist destinations in the nation, with construction of more bridle paths and two hotels. The Summit House opened in 1852, a 64-foot-long (20 m) stone hotel anchored by four heavy chains over its roof. In 1853, the Tip-Top House was erected to compete. Rebuilt of wood with 91 rooms in 1872–1873, the Summit House burned in 1908, then was replaced in granite in 1915.^[13] The Tip-Top House alone survived the fire; today it is a state historic site, recently renovated for exhibits. Other Victorian era tourist attractions include a coach road (1861)—now the Mount Washington Auto Road—and the Mount Washington Cog Railway (1869), both of which are still in operation.^[16]

For forty years, until 1917, an intermittent daily newspaper, called Among the Clouds, was published by Henry M. Burt at the summit each summer.^[17][18]

In 2011 and 2012, Orlando, Florida–based CNL Financial Group, which at the time operated the Mount Washington Hotel at the foot of the mountain, trademarked the "Mount Washington" name when used with a resort or hotel. CNL officials said they were directing their efforts only against hotels and not the numerous businesses in the area that use the name.^[19] CNL's application at the U.S. Patent and Trademark Office seeks registration of the trademark "Mount Washington" for any retail service, any restaurant service, and any entertainment service.^[20]

Climate

The summit station of Mount Washington has an alpine climate or tundra climate (Köppen ET), although it receives an extremely high amount of precipitation, atypical for most regions with such cold weather. However, elevations just beneath treeline have a subarctic climate (Köppen Dfc) which eventually transitions to a humid continental climate (Köppen Dfb) near the mountain's base and the surrounding lower elevations.^[22]

The weather of Mount Washington is notoriously erratic. This is partly due to the convergence of several storm tracks, mainly from the Atlantic to the south, the Gulf region and the Pacific Northwest. The vertical rise of the Presidential Range, combined with its north–south orientation, makes it a significant barrier to westerly winds. Low-pressure areas are more favorable to develop along the coastline in the winter due to the relative temperature differences between the northeastern United States and the Atlantic Ocean. With these factors combined, hurricane-force wind gusts are observed from the summit of the mountain on average of 110 days per year. These extreme winds also contribute to the mountain's very short treeline, with elevations as low as 4,400 feet (1,300 m) being too hostile to support any plant life more than a few inches (centimeters) in height.^[23][24]

Mount Washington once held the world record, and still holds the Northern Hemisphere and Western Hemisphere record, for directly measured surface wind speed, at 231 mph (372 km/h), recorded on the afternoon of April 12, 1934. A new wind speed record was discovered in 2009: on April 10, 1996, Tropical Cyclone Olivia had created a wind gust of 408 km/h (254 mph) at Barrow Island off the western coast of Australia.^[25]

The first regular meteorological observations on Mount Washington were conducted by the U.S. Signal Service, a precursor of the National Weather Service, from 1870 to 1892. The Mount Washington station was the first of its kind in the world, setting an example followed in many other countries. For many years, the record low temperature was thought to be −47 °F (−43.9 °C) occurring on January 29, 1934, but upon the first in-depth examination of the data from the 19th century at NOAA's National Climatic Data Center in Asheville, North Carolina, a new record low was discovered. Mount Washington's official record low of −50 °F (−45.6 °C) was recorded on January 22, 1885. The official record low daily maximum is −28 °F (−33.3 °C) on February 6, 1995.^[21] Highs of 0 °F (−18 °C; 255 K) or below occur on 13 days annually, while lows at or below 0 °F (−18 °C; 255 K) can be expected from November 17 through April 1; from December to March, temperatures rise above freezing (0 °C (32 °F; 273 K)) on only 15 days.^[21]

On January 16, 2004, the summit weather observation registered a temperature of −43.6 °F (−42.0 °C) and sustained winds of 87.5 mph (140.8 km/h), resulting in a wind chill value of −102.59 °F (−74.8 °C) at the mountain.^[26] During a 71-hour period from approximately 3 p.m. on January 13 to 2 p.m. on January 16, 2004, the wind chill on the summit never went above −50 °F (−45.6 °C).^[26] The official record high temperature at the summit is 72 °F (22.2 °C) on June 26, 2003, and August 2, 1975,^[27] while the official record high daily minimum is 60 °F (15.6 °C), recorded on the latter date.^[21] Readings of 60 °F (15.6 °C) or higher at the summit are seen an average of 13.5 days annually.^[28]

On February 3–4, 2023, overnight wind gusts of over 100 miles per hour (160 km/h) and a temperature of −47 °F (−43.9 °C) combined to produce a new US record low windchill temperature of −108 °F (−77.8 °C),^[29] breaking the previous figure of −103 °F (−75.0 °C).^[30][31] Temperatures remained at or below -45 °F for 13 straight hours on February 3–4, 2023, and a -47 °F reading from the morning of February 4, 2023 was the coldest reading in 89 years, tying a previous record low observed in January 1934.^[32]

The primary summit building was designed to withstand 300 mph (480 km/h) winds; other structures are chained to the mountain.^[33] In addition to a number of broadcast towers, the mountain is the site of a non-profit scientific observatory reporting the weather as well as other aspects of the subarctic climate of the mountain. The extreme environment creates strong winds and ice at the top of Mount Washington making the use of unmanned equipment problematic. The observatory also conducts research, primarily the testing of new weather measurement devices. The Sherman Adams summit building, which houses the observatory, is closed to the public during the winter^[34] and hikers are not allowed inside the building except for pre-arranged guided tours.^[35]

In 1932, the Mount Washington Observatory was built on the summit through a group interested in and noting the worth of a research facility at that demanding location.^[36] The observatory's weather data have accumulated a climate record since. Temperature and humidity readings have been collected using a sling psychrometer, a simple device containing two mercury thermometers. Where most unstaffed weather stations have undergone technology upgrades, consistent use of the sling psychrometer has helped provide scientific precision to the Mount Washington climate record.^[37]

The observatory makes prominent use of the slogan "Home of the World's Worst Weather", a claim that originated with a 1940 article in Appalachia magazine by Charles Brooks, the man generally given the majority of credit for creating the Mount Washington Observatory. The article was titled "The Worst Weather in the World" even though it concluded that Mount Washington most likely did not have the world's worst weather.^[35][38]

Image gallery

• 
  Mount Washington Observatory
• 
  The original weathered shingle-clad building is chained to the ground, here covered in rime ice in early April.
• 
  The summit of Mount Washington is frequently obscured by clouds.

Precipitation

Due in part to its high prominence, to its situation at the confluence of two major storm tracks, and to the north–south orientation of the Presidential Range ridgeline, which it crowns, Mount Washington receives high levels of precipitation, averaging an equivalent of 91.2 in (2,320 mm) of rain per year,^[b] with a record high for a calendar year of 130.14 in (3,305.6 mm) in 1969^[39] and a low of 71.34 in (1,812.0 mm) in 1979. Monthly precipitation has ranged from 0.75 in (19.1 mm) in October 1947 to 28.70 in (729.0 mm) in October 2005.^[27] Large amounts of precipitation often fall in a short period of time: in October 1996, a record 11.07 in (281.2 mm) of precipitation fell during a single 24-hour period. A substantial amount of this falls as snow, with a seasonal^[c] average of around 280 inches (7.1 m) of snow; seasonal accumulation has ranged from 75.8 in (1.93 m) in 1947–48 to 566.4 in (14.39 m) in 1968–69.^[21] The record amount of snowfall in a 24-hour period, 49.3 in (125.2 cm), occurred in February 1969, which is also the snowiest month on record with 172.8 in (4.39 m).^[27]