New Ymkk State 



39 



degrees or more below zero, generally over the Northern Plateau, 

 and that temperatures of 35 degrees below zero are not uncommon 

 over the elevated parts of the Eastern and Western plateau 

 divisions. 



But it is in the relative freedom from excessive cold along the 

 Great Lakes that interest centers chiefly, for in this is found the 

 explanation of the successful fruit growing in that section. Only 

 Long Island and a small part of the adjacent coast enjoys greater 

 freedom from excessive cold in winter. 



FROSTS 

 The term " frost " is used to designate a deposit of ice crystals 

 on the surface of plants or other objects, and also temperatures 

 that are injurious to vegetation. Weather bureau observers use 

 the term in the latter sense, and record three degrees of frost — 

 light, heavy, and killing. Light frost is recorded when only the 

 tenderest plants are injured, heavy when the injury is more 

 marked, and killing when the staple crops of the region are killed 

 or badly injured. 



Fig. 12. — Average Number of Days Between the Last Frost in Spring 

 and the First in Fall 



