Climate.—The climate is hot and moist, the medium temperature reaching 104 degs. F. Constant rains and winds from the east cool the heavy atmosphere of the low regions. On the heights of the Central Cordillera the temperature is healthy and agreeable.
Iron rusts and becomes consumed, so that nothing can be constructed of this metal. Even bronze artillery has to be covered with a strong varnish to protect it from the damp winds.
Although one would suppose that all the large islands in the Tropics enjoyed the same climate, yet from the greater mortality observed in Jamaica, St. Domingo, and Cuba, as compared with Porto Rico, one is inclined to believe that this latter island is much more congenial than any of the former to the health of Europeans. The heat, the rains, and the seasons are, with very trifling variations, the same in all. But the number of mountains and running streams, which are everywhere in view in Porto Rico, and the general cultivation of the land, may powerfully contribute to purify the atmosphere and render it salubrious to man. The only difference of temperature to be observed throughout the island is due to altitude, a change which is common to every country under the influence of the Tropics.
In the mountains the inhabitants enjoy the coolness of spring, while the valleys would be uninhabitable were it not for the daily breeze which blows generally from the northeast and east. For example, in Ponce the noonday sun is felt in all its rigor, while at the village of Adjuntas, 4 leagues distant in the interior of the mountains, the traveler feels invigorated by the refreshing breezes of a temperate clime. At one place the thermometers is as high as 90 deg., while in another it is sometimes under 60 deg. Although the seasons are not so distinctly marked in this climate as they are in Europe (the trees being always green), yet there is a distinction to be made between them. The division into wet and dry seasons (winter and summer) does not give a proper idea of the seasons in this island; for on the north coast it sometimes rains almost the whole year, while sometimes for twelve or fourteen months not a drop of rain falls on the south coast. However, in the mountains at the south there are daily showers. Last year, for example, in the months of November, December, and January the north winds blew with violence, accompanied by heavy showers of rain, while this year (1832) in the same months, it has scarcely blown a whole day from that point of the compass, nor has it rained for a whole month. Therefore, the climate of the north and south coasts of this island, although under the same tropical influence, are essentially different.
As in all tropical countries, the year is divided into two seasons—the dry and the rainy. In general, the rainy season commences in August and ends the last of December, southerly and westerly winds prevailing during this period. The rainfall is excessive, often inundating fields and forming extensive lagoons. The exhalations from these lagoons give rise to a number of diseases, but, nevertheless, Porto Rico is one of the healthiest islands of the archipelago.
In the month of May the rains commence, not with the fury of a deluge, as in the months of August and September, but heavier than any rain experienced in Europe. Peals of thunder reverberating through the mountains give a warning of their approach, and the sun breaking through the clouds promotes the prolific vegetation of the fields with its vivifying heat. The heat at this season is equal to the summer of Europe, and the nights are cool and pleasant; but the dews are heavy and pernicious to health. The following meteorological observations, carefully made by Don Jose Ma. Vertez, a Captain of the Spanish navy, will exhibit the average range of temperature:
Ds of heat observed in the capital of Porto Rico, taking a medium of five years.
Degrees of Heat Observed in the Capital of Porto Rico, Taking a Medium of Five Years.
Hours of the Day. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.
Seven in the morning 72 72 1/2 74 78 78 82 85 86 80 1/2 77 75 75
Noon 82 81 82 83 85 86 90 92 88 85 84 80
Five in the evening 78 74 78 80 81 84 87 90 83 82 80 79
The weather, after a fifteen or twenty days' rain, clears up and the sun, whose heat has been hitherto moderated by partial clouds and showers of rain, seems, as it were, set in a cloudless sky. The cattle in the pastures look for the shade of the trees, and a perfect calm pervades the whole face of nature from sunrise till between 10 and 11 o'clock in the morning, when the sea breeze sets in. The leaves of the trees seem as if afraid to move, and the sea, without a wave or ruffle on its vast expanse, appears like an immense mirror. Man partakes in the general languor as well as the vegetable and brute creation.