,THE FACTORS WHICH DETERMINE CLIMATE 293 



temp erature of any locality on the map. Chicago, for instance, has 

 erage temperature for July of about 71 or 72; St. Louis, of 

 76 or 77; New Orleans, of about 82. For January, Chicago 

 i average temperature of about 22; St. Louis, of about 29; and 



Orleans, of about 52. 



an a 

 abou 

 has a 

 New 



About what average temperature has Boston for July? New 

 York City? Baltimore? Charleston, S. C. ? New Orleans? Santa 

 Fe, N. Mex.? San Francisco? Denver? Bismarck, N. D.? St. 

 Paul, Minn.? Portland, Oregon? 



FIG. 219. Average temperature for January, 25 years. 



Estimate the average temperature of each of these places for 

 January. 



B. RELATIVE HUMIDITY 

 316. Seasonal Changes in Relative Humidity. 



Exercise 70. Study of the Average Relative Humidity of the United 

 States, Summer Months and Winter Months, Figs. 220 and 221 



Taking the United States as a whole, is the relative humidity higher 

 in the summer or in the winter? 



Locate several cities such as Chicago, Pittsburg, Charleston, 



