 Both these wind zones, Intertropical Convergence Zones and Temperate zones, have different wind patterns that cause dry climates in various parts of the country.Due to the different wind zones, two-thirds of Mexico is considered to be arid to semi-arid as the only receive about 500 mm of rain year round.The other third of the country is categorized as humid  and various greatly from the previous two-thirds, as the remaining third receives more than 2000 mm of rain all year.