Acquiring water is a challenge for desert animals, and organisms inhabiting arid regions have evolved morphological, physiological, and behavioral traits to maintain an appropriate water balance. On four occasions, I observed rain-harvesting or observed behaviors suggestive of rain harvesting in a population of speckled rattlesnakes (Crotalus mitchellii) in the Mojave Desert of southwestern North America. Snakes collected rainwater on the surface of their bodies and subsequently drank it. Speckled rattlesnakes also drank rainwater that accumulated in structural features of their habitat (e.g., surface of rocks). My observations suggest that C. mitchellii may engage in rain-harvesting when thermal conditions are not optimal (i.e., during cold temperatures). For instance, rattlesnakes presumably emerge from hibernation to take advantage of rainwater.