A mathematical model has been developed to predict wafer temperatures within a hot‐wall multiwafer low pressure chemical vapor deposition (LPCVD) reactor. The model predicts both axial (wafer‐to‐wafer) and radial (across‐wafer) temperature profiles. Model predictions compare favorably with in situ wafer temperature measurements described in an earlier paper. Measured axial and radial temperature nonuniformities are explained in terms of radiative heat‐transfer effects. A simulation study demonstrates how changes in the outer tube temperature profile and reactor geometry affect wafer temperatures. Reactor design changes which could improve the wafer temperature profile are discussed.