AGRICULTURAL RESOUEOES, ETC., OF PORTO RICO. 7 



ning. Eainy days are rare, but rainy afternoons or evenings — for an hour or two — 

 common. The rain begins suddenly, falls heavily, and ends soon. There is no 

 impression of rainy climate, except that everything seems constantly fresh and 

 clean. 



The healthfuluess of San Juan is the greatest of any city in the West Indies. 

 Yellow fever is never at home here, and when imported it rarely, if ever, 

 spreads. * * * 



The climate of the rest of the island is much like that of San Juan, with modifi- 

 cations due to elevation above the sea and to changes in the "briza" due to the 

 topography. The change of the temperature with elevation is relatively rapid 

 here, being approximately 4" of temperature to every 1,000 feet. 



Now, Mount Yunque, at the northeastern part of the island, is, according to the 

 chief of the department of engineers of the island, about 6,000 feet high, and its 

 summit would have a mean temperature as low as that of many places in the States. 

 Besides, elevations of 2,000 feet are not unusual for towns; snow apparently never 

 falls upon the islands, but hoarfrosts are reported as occasional in high places. 

 Several towns of some size in the interior have a popular reputation as being cold — 

 Cayey, Adjuntas, and Utuado. That black frosts do not occur, however, is evi- 

 dent from the fact that the banana grows freely up to at least 2,000 feet, and is 

 very sensitive to frost. 



There appear to be three mountain ridges running from end to end in the island, 

 but the central is the commanding one, and the elevations are, on the whole, high- 

 est toward the eastern end, and especially at the northeastern angle. The result 

 is that the "briza" most wets and refreshes the eastern end of the island, and the 

 rainfall changes greatly from point to point. Judging by Jamaica, of which the 

 climate has been carefully studied, the heaviest rainfall is in the northeast, and it 

 may here in places amount to 100 inches annually or more. In Jamaica it is 

 known to surpass 300 inches in some places, and El Yunque, as seen from San 

 Juan, is very generally capped by a rain cloud. The interior valleys of the island 

 are relatively dry, while the northern and eastern mountain slopes are wet. 



The following summary, taken from the United States ^Veather 

 Bureau report for Porto Rico, shows the temperature, rainfall, cloudy 

 and clear days, and wind velocity at San Juan for one year : 



Summary for twelve months. 



Month. 



November, 1898 

 December, 1808 - 

 Jaauary,1899--- 

 February, 1899. 



March, 1899 , 



April, 1899 



May, 1899 



June, 1899 



July, 1899 



August, 1899 ..., 

 September, 1899 

 October, 1899 ... 



Highest 

 tempera- 

 ture. 



Lowest 

 tempera- 

 ture. 



65 



Date. 



'18 

 19 

 2 20 

 8 

 i 

 1 

 6 

 54 



20 



30 



1 



Mean. 



' F. 

 77.3 

 75.9 

 74.0 

 75.2 

 74.7 

 76.6 

 79 

 79.4 



Greatest 

 daily 

 range. 



' F. 



18 

 17 

 13 

 10 

 15 

 16 

 17 

 17 

 16 

 16 

 14 

 17 



Least 

 daily 

 range. 



Cloudy 

 days. 



Partly 

 cloudy 

 days. 



Clear 

 days. 



Kain. 



Maxi- 

 mum ve- 

 locity 

 of wind, s 



November, 1898 

 December, 1898 

 January, 1899 . . 

 February, 1899. 

 March, 1899,... 



April, 1899 



May, 1899 



June, 1899 



July, 1899 



August, 1899... 

 September, 1899 

 October, 1899 . . 



«2 



«12 

 22 



19 

 21 

 20 

 11 



7 

 11 



i 

 13 



Inches. 



12.08 



5.34 



2.92 



.80 



2.29 



6.09 



2.59 



7.23 



7.53 



10.38 



1.3.66 



10.21 



23 

 20 

 21 

 24 

 19 

 24 

 19 

 '66 

 31 

 38 



■ Also 19, 22. 

 = Also 28. 



3 Also 7, 19, 20, 29, 30. 

 < Also 4, 32, 27. 



» Also 8, 27, 28. 



^ Beginning Nov. 13. 



' Eighth, east. 

 ® Miles per hour. 



