all night long; all through the night
Adverb describing an action or state that continues throughout the entire night.
昨夜は一晩中雨が降っていた。
It rained all night long last night.
彼は一晩中勉強した。
He studied all through the night.
I stayed up all night studying before the exam.
The baby cried all night, and the parents couldn't sleep.
The snow kept falling all through the night.