16 RURAL MICHIGAN 



CLIMATE OF MICHIGAN 



The effects of the Great Lakes are not confined 

 to the obvions rehitions with commerce. They liave 

 a definite influence on the climate of Michigan. Lake 

 Superior has an area of 31,810 square miles. The 

 superficial area of Lake Michigan is 22,400 square 

 miles; of Lake Huron, 23,010; of Lake Erie, 9,940; 

 and of Lake St. Clair, 460. Thus these five lakes 

 have a total area of 87,620 square miles. The depth 

 of Lake Superior reaches 1,180 feet; of Lake Mich- 

 igan, 870; of Lake Huron, 750; of Lake Erie, 210, 

 and of Lake St. Clair, 24 feet. Obviously this mass 

 of water absorbs an immense vohnne of solar heat 

 in summer and rehictantly yields it up again to the 

 contiguous atmosphere, thus raising winter and lower- 

 ing summer temperatures in the region within the 

 scope of their influence. 



The records of the United States Weather Bureau 

 taken at points on Lake Erie show a midsummer 

 temperature ranging as high as 78 degrees during a 

 period of more than eight years at Toledo, while 

 Lake Huron and Lake Michigan averages run a few 

 degrees cooler. The much greater volume of water 

 in Lake Superior and its more northerly latitude 

 keep its summer temperature well below that of its 

 southerly relatives; yet here, too, the warming up 

 process of July and August carries its surface ther- 

 mometric readings to a point above 60 degrees. That 

 the midwinter temperatures of all these lakes run 



