"violent storm," mid-13c., from Old French tempeste (11c.), from Vulgar Latin *tempesta, from Latin tempestas (genitive tempestatis) "storm, weather, season," also "commotion, disturbance," related to tempus "time, season" (see temporal). Sense evolution is from "period of time" to "period of weather," to "bad weather" to "storm." Words for "weather" were originally words for "time" in languages from Russia to Brittany. Figurative sense of "violent commotion" is recorded from early 14c.