A nonisothermal extension of the coalescence-dispersion (CD) model was developed to study the effects of micromixing on the bistability of adiabatic first-order reactions in continuously fed stirred tank reactors. The predictions of this nonisothermal CD model, which can also be used to calculate unstable solution branches, closely agree with calculations from the nonisothermal interaction exchange with the mean (IEM) model when the characteristic mass and thermal micromixing times are identical. The model predicts that micromixing has little effect on the overall conversion and temperature on the flow branch for adiabatic first-order reactions. However, the exit temperature distributions can be significantly altered as the mixing becomes decreasingly efficient. In contrast, mixing significantly influences the overall conversion and temperature when the reactor operates on the thermodynamic branch, but the exit temperature distributions show little qualitative change.