160 



IOWA ACADEMY OF SCIENCES. 



January . . . 

 January. . . 

 January . . . . 

 I'ebruary. . . 

 Februaiy . . . 

 February. . . 



March 



March 



March 



April 



April . ... 



April 



May 



Mav 



JViay .. 



June 



June 



June 



July 



Julv 



July 



Au.,u.st 



Aujj^upr. . . . 



Auj<u-^t 



September.. 

 Septem er.. 

 Seyieriibei . . 

 ()c*<)h( r . . 



Octfiber 



October 



November. . 

 Novembc-r. . 

 November. . 

 December . . 

 December. . 

 Deceiijber. . 



CHARACTER OF TIIR DAYS. 



Clear days. . . 

 Partly cloudy 



Cloudy 



Clear days . 

 Partly cloudy. 



t loudy 



Clear days. . . 

 Partly cloudy 



1 ludy 



'. lear days . . 

 P.irily cloudy 

 Cloudy. . . . 

 Clear days. . . 

 P.titly cloudy 

 Cloudy. 

 Clear days. . . 

 Paitly cloudy 



Clcudy .'. 



■ lear days. . . 

 Partly cloudy 



Cloudy 



Cie ir days . . 

 Partly cloudy 



Clcudy 



Cle;ir days. . . 

 Tarilv cloudy 



< loudy 



C'lear days. . . 

 I'at ilv cloudy 

 i. loudy 



lear davs. . . 

 Partly cloudy 



^ loudy 



Clear days. . . 

 T'artly cloudy 

 Cloudy, 



Total clear days 



Total partly cloudy days. 

 Total cloudy days 



Prevailing Winds— 



Total clear days 



Partly cloudy days. 

 Cloudy davs 



Heat is an important factor in the development of 

 plants. Tlie plant zones of Humboldt were established by 

 connecting the points having the same mean annual tem- 

 perature. He called these isothermal lines. On this basis 

 there were established the Boreal, Austral and the Tropical 



• Not reported. 



