americasgreatoutdoors: The coldest temperature ever recorded in Yellowstone National Park, Wyoming w
americasgreatoutdoors: The coldest temperature ever recorded in Yellowstone National Park, Wyoming was -66°F on February 9, 1933. When temperatures get that cold and there’s no wind, water vapor will freeze to things like grasses, trees and rocks, known as hoarfrost. Do you get hoarfrost where you live? Photo by Jacob W. Frank, National Park Service. -- source link