Climatological Dispersion Model-Version 2.0 (CDM-2.0) determines long-term (seasonal or annual) quasi-stable pollutant concentrations in rural or urban settings using average emission rates from point and area sources and a joint frequency distribution of wind direction, wind speed, and stability. The Gaussian plume hypothesis forms the basis for the calculations. Computations can be made for up to 200 point sources and 2500 area sources at an unlimited number of receptor locations. CDM-2.0 includes the following options: 16 or 36 wind-direction sectors, initial plume dispersion, buoyancy-induced dispersion, stack-top down wash, and gradual (transitional) plume rise. The user has a choice of seven dispersion parameter schemes. Software Description: The software is written in the FORTRAN programming language for implementation on an IBM-PC compatible microcomputer. Data is in compressed format but a dearchive utility is included.