Why is Venezuela so dry? I'm trying to understand why the summer (January) precipitations in Venezuela are so low in the central and southern parts of the country as well as in eastern Colombia. The most plausible explanation I could find was a rain-shadow effect but unless I'm wrong, the mountains are on the northern side while the winds are blowing from the ocean, east to west. This should not result in a dry season. 

What have I missed?

My references are : 

http://research.jisao.washington.edu/data_sets/ud/samerica/

http://kids.britannica.com/comptons/art-166714/The-map-at-left-shows-the-wind-belts-of-the
In January the Intertropical Convergence Zone shifts to south of the equator. And the Subtropical High Pressure Belt moves into areas of Venezuela, which leaves it dry. I am guessing this from a study of principles of world geography and climatology; I don't live in Venezuela though.