adverb, adverb taking the 'to' particle, noun or participle which takes 'suru'
gently raining; drizzling
Describes soft, quiet, persistent rain. Often used with 降る or in the form しとしとと.
朝から雨がしとしと降っている。
It has been drizzling since morning.
しとしとと降る雨
I walked in the gently falling rain.
na-adjective
Describes a surface or atmosphere that is slightly wet, often with a soft, lingering quality. Less common than the rain sense.
しとしとした空気が肌にまとわりつく。
The damp air clings to my skin.