also: しょうう · こあめ
noun
Refers to rain that is not heavy, typically with small drops and low intensity. The reading こさめ is the everyday term; しょうう is literary/formal, and こあめ is rare.
朝から小雨が降っている。
A light rain has been falling since morning.
小雨の中を散歩するのは
It's pleasant to take a walk in a drizzle.