CENTRAL AMERICAN RAINFALL. 
17 
ford also says: * “ The rainfall diminishes as we ascend the 
River San Juan, and after passing the mouth of the San 
Carlos the weather is bright and pleasant in the dry season, 
vegetation is not so rank, the land is well adapted to agri¬ 
culture, and, as it is sufficiently damp for the growth of 
grass, cattle raising is an easy and lucrative business.” 
IV. The fourth type is one of transition. It is one in 
which the zenithal maxima of the invierno of higher lati¬ 
tudes are separating from each other in preparation for 
change into the opposite months of the year south of the 
meteorologic equator. The verano is well marked but brief— 
January, February, and March. The maxima are in April 
and November, and the summer dry season is here extended, 
but only relatively dry, while there is a brief drier season. 
There is also a season at the end of June when the rains are 
altogether suspended, but this is too brief to be noticeable 
on the diagram. This is the veranito or verano of St. John. 
The succession of the seasons is given by the Hydro- 
graphic Office in their Coast Pilot: t 
The wet season commences in May and lasts till November. The 
rainfall gradually increases until it is fairly established in June, and con¬ 
tinues through July, August, and September, with strong southerly winds. 
In December the rains cease, the northw r est and north-northwest winds 
set in, producing an immediate change. During the dry season regular 
land and sea breezes blow. The sea breeze sets in about 10:30 a. m. from 
south-southwest, and generally increases in force until about 3:30 p. m., 
after which it gradually subsides and at sundown is quite calm. 
5. Distribution through the Day at San Jose , Costa Rica .— 
The rainfall of the invierno has a marked diurnal periodic¬ 
ity ; with the trade-wind rainfall this periodicity is less 
marked, and with the rain from cyclonic sources or from 
northers the diurnal variation is nearly suppressed. The 
diurnal features are, therefore, best marked in the region 
of typical invierno , and, as a matter of fact, the observations 
*43d Cong., 1st session, Sen. Ex. Doc. No. 57, 1874, p. 114. 
t Publication No. 84. West Coast of Mexico and Central America, etc. 
8°. 2d edition, 1893, p. 238. 
3—Bull. Phil. Soe., Wash.. Vol. 13. 
