MARYLAND WEATHER SERVICE 



41 



well. Mr. Walz's map shows a difference of 39 days in the date of 

 the advent of spring at Pocomoke City and Sunnyside, as con- 

 trasted with the difference of 30 days in the date of the last occur- 

 rence of 32°, and 71 days in the date of the last occurrence of 40°. 

 While the difference between the date of arrival of spring at the 

 extreme end of the state which is indicated in this map is approxi- 

 mately correct, the actual dates given are about 10 days too early, 

 so far as concerns the greatest mass of unfolding of foliage in de- 

 ciduous trees. 



Humidity. — Data on atmospheric humidity are available only for 



Fig. 3. — Map of Maryland Showing Annual Precipitation in Inches. 



Baltimore, and would probably be found to differ for the other sta- 

 tions in very nearly the same proportion as does the rainfall. The 

 data for Baltimore from 1S93 to 1903 are as follows: 



January, 6S.3; February, GG.O ; March, G6.S ; April, 60.6; May. 

 65.1; June, 68.0; July, 67.1; August, 69.0; September, 70.4; 

 October, 07. 7: November, 66.3; December, 67.6; Year, 66.86%. 



Bain-fall. — The uniformly favorable conditions of rain-fall 

 throughout the state for the development of the highest types of 

 plant-life make a comparison of the rain-fall data for the different 

 stations selected of less importance than in the case of temperature. 



