Mount Washington in the White Mountains of New Hampshire has recorded the coldest temperatures in the contiguous 48 states and the highest surface wind measurement. On January 22, 1885, the lowest official temperature reached -50º Fahrenheit (-46º Centigrade). Only Cyclone Olivia in the South Pacific reached higher recorded surface wind speeds than the 231 mph (372 km/hour), which occurred there on April 12, 1934.
As extreme as the temperature gets, you can easily travel up to the top using the historic cog railway (built in 1869). If you go, be sure to bundle up, else you will turn into an icicle.
The reason why Mount Washington has such extreme temperatures is explained as follows by Wikipedia:
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 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 systems are more favorable to develop along the coastline in the winter months due to the relative temperature differences between the Northeast 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.
Suffice it to say, the cog railway does not run when the climactic conditions are unfavorable. The folks there don’t want their tourists blown to Oz and beyond.