188 THE CLIMATE OF PRINCE GEORGE^S COUNTY 



being known as Sontliern Maryland. It includes St. Mary's, Cal- 

 vert, Charles, and Anne Arundel counties, and all but the extreme 

 western margin of Prince George's County. 



The characteristics of the Coastal Plain, important from a climatic 

 standpoint, are its low, level lands, composed mostly of unconsoli- 

 dated sands and clays, and the deep indentation of the region by 

 Chesapeake Bay, its rivers and tributaries. The elevation of the 

 land is considerably higher in the western peninsula than in eastern 

 Maryland, frequently exceeding 100 feet even along its eastern mar- 

 gin, and reaching 280 feet farther west near Washington. 



Elevation does not, however, enter as an important climatic factor 

 in determining the weather of the county and hence marked climatic 

 differences are not to be expected. The causes that determine the 

 prevailing weather in this area are to be found in general rather than 

 local conditions and depend very largely upon the geographical 

 position of the county with reference to the paths usually followed 

 by the great storm areas as they move across the country. As these 

 matters have been fully elaborated in Volume I of the Maryland 

 State Weather Service further discussion in this connection will not 

 be necessary. 



Meteorological Data Available for Prince George's County. 



The discussion of the climate of Prince George's County and the 

 District of Columbia is greatly facilitated by the fact that there are 

 such a large number of stations from which reports have been 

 secured. Furthermore, these records, notably those from Washing- 

 ton, are especially valuable not only because they extend back over 

 a longer period of time than the majority of available climatological 

 records but also by reason of the fact that they were made by experts 

 using the very best known instruments exposed in the most approved 

 scientific manner. 



Practically all the meteorological observations made at the fol- 

 lowing stations were made under the auspices of some organization 

 or institution. It may be well to state briefly the more essential 

 points in each system concerned as the instrumental equipment and 

 hours of observation are uniform for each. 



