An activation energy asymptotic theory for methanol droplet combustion in microgravity is presented by extending earlier models to account for time-dependent water dissolution or evaporation from the liquid droplet. The model predictions for droplet extinction diameter as a function of its initial diameter are shown to compare favorably with experimental results for methanol burning in air. (c) 2013 The Combustion Institute. Published by Elsevier Inc. All rights reserved.