54 



Eleventh Annual Report 



nual mean temperature. The cold area in the eastern part of the 

 State, and the warm conditions in the lower half of the Wabash 

 Valley are clearly defined and similarly outlined on both charts. 



These areas are also found to be equally well preserved on the 

 chart (Plate 5) of the average date of first killing frost in autumn. 

 There is a striking resemblance between the two frost charts. This 

 illustrates well the fact that the advance of the spring and autumn 

 seasons is regular and, in the same locality, similar climatic in- 

 fluences prevail during both seasons. It will be noted that each 

 chart shows a range of about twenty-eight days between the ex- 

 treme ends of the State in the average time of occurrence of the 

 first and last killing frost. It is thus shown that, while the 

 district lying along the Ohio River in Indiana has a growing sea- 

 son of practically 200 days, the extreme northern and east-central 

 portions have little more than 140 days. This difference of about 

 eight weeks causes a great diversity in the nature of crops grown 

 in the State. 



z 







^% 



-J 





o 



Wi 



-^ 



i\m\m\m\m 



Fig. 1. Average monthly precipitation for Indiana. 



