This is the 7947th most frequent Japanese word.
夏期
"Summer term" or "summer season."
夏期 in this sentence is used to denote 'summer term' or 'summer period,' referring to a specific timeframe designated for educational courses.
夏期講習に参加しました。
I participated in the summer training course.
夏期 is used here to describe the operational period of the pool, specifically the summer season.
このプールは夏期のみ営業しています。
This pool is open only during the summer season.
In this sentence, 夏期 refers generically to the summer season or the duration of summer, highlighting its climate characteristics.