I used to work for the AMC and would take the Mt Washington Auto Road multiple times per week in order to service on the Lake of the Clouds building on Washington. It is an awesome ride and with nice weather the views are outstanding. However, when the weather is bad it is horrible. I have seen 90mph sideways snow up there in June and July in years past.
On a slightly related note, we were heli lifting gear to some of the backcountry buildings on the day Travas Pastrana and Red Bull broke the Mt Washington hill climb record, it was pretty awesome to watch and his exhaust could be heard for miles.
Here is the video for anyone interested.