THE BAHAMA ISLANDS 117 



MEAN RELATIVE HUMIDITY. 



3 P. M. * Daily Mean. 



Per Cent. Per Cent. 



74 82 



74 82 



69 77 



70 78 



68 77 

 73 78 



75 80 



69 75 

 73 80 

 72 79 



69 76 



70 79 



71 78 

 * Corrected to daily means based on 24 hourly observations. 



CLOUDS AND SUNSHINE. 



There is an abundance of bright sunshine throughout the year. The 

 Islands being within the westward extension of the area of high barometric 

 pressure over the Atlantic Ocean a large portion of the year share with this 

 area much of its fine weather. Overcast skies are not persistent. The aver- 

 age amount of cloudiness does not vary greatly from month to month. It is 

 slightly greater in the summer and fall months than during the winter. 

 Cloudiness is least in January and February and greatest, on the average, in 

 October. The distribution throughout the year is indicated in the following 

 table showing the monthly average values at 9 a. m. and 3 p. m. for a period 

 of five years. 



AVERAGE CLOUDINESS. 

 (10, completely overcast; 0, practically clear.) 

 Jan. Feb. Mar. Apr. May. June. July. Aug. Sep. Oct. Nov. Dec. Year. 



9 a. m 5.0 4.9 5.6 5.6 5.8 7.3 6.7 6.9 7.2 7.8 6.6 6.2 6.3 



3 p. m 4.9 5.3 5.1 5.4 5.6 6.5 7.5 7.4 7.5 7.8 5.9 7.1 6.3 



RAINFALL. 



The rainfall varies greatly in amount from year to year. The average 

 annual fall approximates 50 inches. Fully four-fifths of the total annual 

 precipitation occurs from May to October, leaving but one-fifth for the 

 winter and early spring months. During the five years from 1898 to 1902, 

 the heaviest rainfall occurred in the month of August. During the summer 

 months the rainfall is frequently excessive in amount, but, as a rule, the 

 duration is short. Included in the equipment for a study of the climate of 

 the Islands was an instrument designed to register automatically the begin- 

 nings and endings of rainfall, by means of which a record was obtained of all 

 local rains, both heavy and light, from June 23 to July 19. The record 



