"Snowman" was written by Sia and frequent collaborator Greg Kurstin. Written in the key of D♭ major, Sia's vocals span one octave and a semitone from F3 to G♭4. Production on the track was handled solely by Kurstin. The song is a midtempo, 60's-inspired, piano-driven, crisp, swaying ballad over which Sia's vocals, described as "calm but energetic" by mxdwn, tell a snowman not to cry as he will melt.