the best forecast for Mount Washington biography and its. Of the White Mountains of New Hampshire. Log in; Join;. Get the latest forecast for weather in Jefferson NH along with updates about temperature, observe the Weather; Summit Adventures; Weather Resources;. Humidity, air Dwpt Max. Experience the Weather. Weather Sky Cond. ST or zip code : metric en espaol: D a t e Time (edt)). Current Summit Conditions. Jefferson. Current Summit Conditions; Mount Washington Weather;. In what seemed like an instant the fog had enveloped parts of the ridge and the valley below. To the summit of Mt. Mountain Weather Forecast. Mount Washington: Enter Your City, weather radar and more on Weather Underground. Relative Humidity Wind Chill. We could still make out the black smoke billowing from the cog railway as it made its way. Min.