10 



AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS. 



CLIMATIC FEATURES. 



Rainfall. 



An examination of the precipitation map (see Map 4) shows thst 



the annual rainfall diminishes in regular proportion from east to- 

 west. West of the Pecos River the elevated mountain masses iend to 

 raise the mean annual precipitation over restricted areas, but at the 

 westernmost boundary this average scarcely exceeds 10 inches per year. 

 In the extreme eastern portion of the State the annual rainfall is shown 

 to exceed 50 inches. Between these extremes of wet and dry condi- 

 tions there is a gradual and uniform transition. The precipitation of 

 the State is mostly rainfall, although one or more extensive snow storms 





Map 4 Precipitation of Texas. 



I Over 50 inches ; II Over 45 inches ; III Over 40 inches ; IV Over 35 



inches ; V Over 30 inches ; VI Over 25 inches ; VII Over 20 



inches ; VIII Over 15 inches ; IX Over 10 inches. 



occur annually in the Panhandle region. Snow is rarely known south 

 of Austin. More important than the total amount of rainfall is its 

 distribution during the year, which is exceptionally favorable in Texas. 

 According to the records of the U. S. Weather Bureau, the rainfall 

 curve for the State as a whole has its lowest value in January and 

 February; thence increases to May, after which there is a general de- 

 crease to the close of the year. Grouped by seasons the three winter 

 months, December, January and February, are driest in all portions 

 of the State except along the southeastern Gulf Coast, where the spring 

 months are driest and over a broad area extending from Burleson and 



