THE FACTORS WHICH DETERMINE CLIMATE 299 



velocities, i.e., 10 miles per hour or more, are along the coasts, 

 over the Great Plains Region east of the Rocky Mountains, 

 and in the region of the Great Lakes. 



The records of the Weather Bureau also show the following 

 facts: 



1. The lowest average wind velocities are found in the valleys of 

 the interior. 



2. The greatest wind velocities are found to occur in the months of 



FIG. 224. Average wind velocity, miles per hour. 



March and April, while the lowest velocities occur in the months of 

 July and August. 



3. All high altitudes have a tendency toward high winds, the 

 sharper the point, the higher the winds. 



4. In general the west slope of mountain ranges has a higher aver- 

 age wind velocity than the east slope. 



How do you explain each of these facts? 



There are really two regions of relatively high winds in the 

 interior of the United States: (1) The Lake Region, and (2) the 

 region of the Plains States. The high winds of the Lake 



