The climate of El Peten is tropical with equable temperatures throughout
the year. Temperatures at Chinaja varied between a night-time low of 65 deg.
F. and a daytime high of 91 deg. F. during the time of our visits. In the
Koeppen system of classification the climate at Chinaja and Toocog is Af.
Rain falls throughout the year, but there is a noticeable dry season. To
anyone who has traveled from south to north in El Peten and the Yucatan
Peninsula, it is obvious from the changes in vegetation that there is a
decrease in rainfall from south to north. There is a noticeable
difference between Chinaja and Toocog. Although rainfall data are not
available for Chinaja and Toocog, there are records for nearby stations
(Sapper, 1932). At Paso Caballos on the Rio San Pedro about 40
kilometers northwest of Toocog the average annual rainfall amounts to
1620 mm.; the driest month is March (21 mm.), and the wettest months are
June (269 mm.) and September (265 mm.). At Cubilquitz, Alta Verapaz,
about 35 kilometers south-southwest of Chinaja and at an elevation of
300 meters, the average annual rainfall is 4006 mm.; the driest month is
March (128 mm.), and the wettest months are July (488 mm.) and October
(634 mm.).
During the 18 days in February and March, 1960, that we kept records on
the weather at Chinaja moderate to heavy showers occurred on seven days.
During our stay there in June and July rain fell every day, as it did in
Toocog. However, during the week spent at Toocog in March no rain fell.