The Texas Climatological Model (TCM) Predicts long-term pollutant concentrations for a rectilinear array or receptors defined by the user. This paper describes the TCM and compares predictions from TCM with predictions from the Climatological Dispersion Model (CDMQC). A number of model runs have been made with the TCM and CDMQC using the same source inventories and sets of climatology. The concentrations predicted by these two models are compared and the result of several types of statistical analyses are reported. In most cases, the TCM predicts concentrations that are equivalent to those predicted by the CDMQC. However, in certain cases, the CDMQC tends to predict concentrations that are unrealistically high. In the computer time, the TCM requires about one-eights of the computer time used by the CDMQC.