ephemeral
/ΙΛfem.Ιr.Ιl/Lasting for a very short time; transitory.
"The ephemeral beauty of cherry blossoms reminds us to cherish every moment."
Living or lasting for only a single day or generation, as some plants and insects.
"Mayflies are known for their ephemeral adult lifespan."
Etymology: From Greek ephemeros "lasting only a day", from epi- "upon" + hΔmera "day". First recorded in English in the late 16th century.