A model was developed to predict spatial glass transition temperature (T-g) distributions in glassy maltodextrin particles during transient moisture sorption. The simulation employed a numerical mass transfer model with a concentration dependent apparent diffusion coefficient (Dapp) measured using Dynamic Vapor Sorption. The mass average moisture content increase and the associated decrease in T-g were successfully modeled over time. Large spatial T-g variations were predicted in the particle, resulting in a temporary broadening of the T-g region. Temperature modulated differential scanning calorimetry confirmed that the variation in T-g in nonequilibrated samples was larger than in equilibrated samples. This experimental broadening was characterized by an almost doubling of the T-g breadth compared to the start of the experiment. Upon reaching equilibrium, both the experimental and predicted T-g breadth contracted back to their initial value.