The soil formed in calcareous, clayey alluvium several feet thick. The mean annual precipitation ranges from 24 to 34 inches, and the mean annual temperature ranges from 74 degrees to 76 degrees F. Thornthwaite annual P-E indices range from about 32 to 40. These include the competing Victoria series and the Harlingen , Raymondville , and Tiocano series. Harlingen soils have moist chromas of 1.5 or more in some part of the upper 12 inches in more than half of each pedon. Moderately well drained.
Permeability is very slow.
Runoff is high on slopes less than 1 percent and very high on 1 to 5 percent slopes. Cotton and grain sorghum are the major crops. The series has been mapped and correlated in the Northern, Western, and Lower Rio Grande Valley of the Rio Grande Plain of Texas. Future correlation will restrict this series to the Lower Rio Grande Plain. The series is moderate in extent.