What are the conditions necessary for the formation of sand dunes? Hi, Dunes are formed by interaction with the wind. Wind speeds of 10 to 20 mph,. are necessary for sand to start saltating under the direct pressure of the wind.
Winters are very harsh in Tundra climate. Winter months temperatures are usually between -18 and -50 degrees. Summer temperatures range from 35-50 degrees. High latitudes are the main cause of of the low temperatures. These areas mainly receive indirect sunlight.
Precipitation in the tundra totals 150 to 250 mm a year, including melted snow. That's less than most of the world's greatest deserts! Still, the tundra is usually a wet place because the low temperatures cause evaporation of water to be slow. Much of the arctic has rain and fog in the summers.