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.
Lower elevations have a subarctic climate (Köppen Dfc).

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.

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 coast of western Australia. (
Satellite and radar measurements, e.g. of tornadoes, hurricanes, and air currents in the upper atmosphere, do not officially compete with records for surface measurements.)

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 (−44 °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 (−46 °C) was recorded on January 22, 1885.
The official record cold daily maximum is −28 °F (−33 °C) on February 6, 1995.
Highs of 0 °F (−18 °C) or below occur on 13 days annually, while lows at or below 0 °F can be expected from November 17 through April 1; from December to March, temperatures rise above freezing on only 15 days.

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 (−74.77 °C) at the mountain.
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 (−46 °C).
The official record high temperature at the summit is 72 °F (22 °C) on June 26, 2003, and August 2, 1975, while the official record warm daily minimum is 60 °F (16 °C) on the latter date.
Readings of 60 °F or more at the summit are seen on an average 13.5 days annually.

The primary summit building was designed to withstand 300 mph (480 km/h) winds; other structures are chained to the mountain.
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 and hikers are not allowed inside the building except for pre-arranged guided tours.

The Mount Washington Observatory was built on the summit in 1932 through a group interested in and noting the worth of a research facility at that demanding location.
The observatory's weather data have accumulated a climat
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. Lower elevations have a subarctic climate (Köppen Dfc).
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.
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 coast of western Australia. (Satellite and radar measurements, e.g. of tornadoes, hurricanes, and air currents in the upper atmosphere, do not officially compete with records for surface measurements.)
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 (−44 °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 (−46 °C) was recorded on January 22, 1885. The official record cold daily maximum is −28 °F (−33 °C) on February 6, 1995. Highs of 0 °F (−18 °C) or below occur on 13 days annually, while lows at or below 0 °F can be expected from November 17 through April 1; from December to March, temperatures rise above freezing on only 15 days.
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 (−74.77 °C) at the mountain. 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 (−46 °C). The official record high temperature at the summit is 72 °F (22 °C) on June 26, 2003, and August 2, 1975, while the official record warm daily minimum is 60 °F (16 °C) on the latter date. Readings of 60 °F or more at the summit are seen on an average 13.5 days annually.
The primary summit building was designed to withstand 300 mph (480 km/h) winds; other structures are chained to the mountain. 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 and hikers are not allowed inside the building except for pre-arranged guided tours.
The Mount Washington Observatory was built on the summit in 1932 through a group interested in and noting the worth of a research facility at that demanding location. The observatory's weather data have accumulated a climat
Mount Washington