This climate is characterized by the average temperature of all months
being above 18 deg. C. and the mean-annual rainfall being above 75 cm.
According to the distribution of precipitation this type of climate can
be divided into: (1) areas having periodic rain and wet winters
(southeastern Tamaulipas, south of 22 deg. north latitude and east of 99 deg.
west longitude), and (2) areas having an irregular rainy season and dry
winters (area around Ciudad Mante, between 99 deg. 30' and 98 deg. 30' west
longitude and south of 22 deg. 30' north latitude).