The rainy season on the Caribbean slope of the country does not correspond to that of the Pacific. In fact there are no continuously dry months, and on the northern declivities of the volcanoes of Turialba, Irazú, Barba and Poas, it rains more or less during the entire year; also near Lake Nicaragua it rains nearly continuously, and the mountains of the Guatuso country and the surroundings of the volcano of Orosi are seldom without clouds. At times there are cloud-bursts of tremendous power, broadening rivers for miles. Port Limon is said to have an annual rainfall of eighty-nine inches, but it is greatly exceeded by that of Colon, which averages 120 inches. The mean rainfall at Greytown for 1890, 1891, 1892, was 267 inches yearly. The late United States Commission estimated the average at Lake Nicaragua at eighty inches, and in the basin of the San Juan River at 150 inches. The climate of Talamanca is for the same reason very unhealthy in the proximity of the coast, and also in the lower course of the rivers a similarly deadly climate prevails. In normal years there are two dry and two wet seasons. The rains commence regularly in May or June and last until the end of July. The months of August and September are more or less dry. In October there are some heavy showers, and extensive rains begin which characterize the months of November, December and January. The driest months are February, March and April. The high region is extremely humid, giving rise to fogs and rains. The mosses which almost completely envelop the stems of the trees are constantly dropping water, and the rivers in this section are almost impassable. The climate of the great valley of the Rio Grande de Terraba is similar to that described for the terrace lands. Both regions have distinctly marked characters. Rains begin in April, grow heavier towards September, and cease about the end of November. During the rest of the year dry weather prevails, although sometimes heavy showers relieve this arid condition. In the lower zone pronounced radiation causes a heavy dew and extensive fogs, and both are characteristic of this section. The excessive heat felt on the lowlands diminishes gradually with the rising of the land towards the high mountains, but at times a height of 1500 feet will be found cooler than one of 3000 feet. In the Santa Clara district, for instance, it is cooler at 500 feet elevation than it is in the Reventazon valley at 1500 feet. In general, the torrid lands of the country, ranging from the sea to 150 feet above it, and, if not clear and well-drained, even up to 400 and 500 feet, abound in malarial fevers; but as high ground, having an elevation of from 1500 to 3000 feet is reached, the fevers are of light type and not dangerous, while from 3000 to 5000 feet the diseases are those of the temperate zone, and are due less to local conditions of soil and climate than to personal neglect.