noun, noun which may take the genitive case particle 'no'
summer term; summer period
Refers to a defined summer period, such as a school term, business quarter, or seasonal schedule. Often used in compound expressions like 夏期講習 (summer course) or 夏期休暇 (summer vacation).
夏期講習に参加する生徒が多い。
Many students participate in summer courses.
夏期休暇の予定はもう決まりましたか。
Have you already decided your plans for the summer vacation?
夏季 is the more common word for 'summer season' in general contexts, while 夏期 emphasizes a scheduled period or term.
Compound of 夏 (summer) and 期 (period/term).