152 CUBA AND PORTO RICO 



the other Antilles. The average daily temperature is 80 F., 

 but it is ameliorated by a cooling north breeze which gen- 

 erally prevails during the hottest days. The mean monthly 

 temperature of San Juan, as determined by observations 

 t-xt ending through twenty years, is 78.9 F. The maximum 

 heat, attained only three times during this period, was 99, 

 the minimum 57.2. The thermometer usually rises to 

 88 F. at midday, and sinks to 80.6 F. at night. In the 

 cool mornings it ordinarily stands at 69.8 F., but some- 

 times falls as low as 60.8 F. The interior highlands 

 are cooler, and the nights are sometimes disagreeably so, 

 although snow never falls, and hail but rarely. The cool- 

 est places on the island are Adjuntas, Aibonito, Cayey, 

 Utuado, Lares, and Maricao. 



The hottest months are June, July, August, and Septem- 

 ber ; the coolest, December, January, and February. So far 

 as temperature is concerned, Porto Rico enjoys perpetual 

 summer, the mean monthly temperature hardly varying 

 6 throughout the year, and the extreme limits being 

 within 40 of each other, instead of 118 as at Washing- 

 ton, D. C. 



The disagreeable land winds are seldom felt, though tropi- 

 cal hurricanes are frequent between July and October. The 

 forest-covered central mountains produce a marked differ- 

 ence in the climate between the opposite declivities. The 

 northern side is frequently visited by showers, while the 

 southern district is often without rain for months at a time. 



The average rainfall for the past twenty years has been 

 59.5 inches, or about the same as that of New Orleans, and 

 only six inches less than that of Washington city. The 

 driest month is February, when less than two inches fall. 

 January and March have less than three inches, December 

 less than four. The remaining months, from April to 

 November inclusive, have over five inches of rainfall, the 

 greatest quantity of the year, 7.62 inches, being precipitated 

 in the latter month. 



It rains very hard and abundantly during the hottest 



