夏季|かきkaki[1]atamadaka (head-high)

1. nounsummer season; summer; summertime

• Synonym夏場なつばNeutralSpoken native word for the summer period, often tied to business or weather; 「夏季」 is formal Sino-Japanese for summer as one of the four seasons.
• SynonymサマーCasualColloquial loanword, mostly inside compounds like 「サマーセール」; 「夏季」 is the formal Sino-Japanese term.
• Synonym夏なつNeutralThe everyday word for summer, by far the most common; 「夏季」 is the formal written term, as in 「夏季オリンピック」.
• Synonym夏期かきFormalFormal word for a stretch of time in summer, typical of courses and holidays, as in 「夏期講習」; 「夏季」 points to the season itself.
• Synonym夏時かじWrittenWritten, rare word for the summer season; 「夏季」 is far more common in ordinary use.
• Related九夏きゅうかWrittenWritten, elegant name for the roughly ninety days of summer; 「夏季」 is the ordinary formal term.
• Related夏げNeutralThe everyday word for summer, by far the most common; 「夏季」 is the formal written term, as in 「夏季オリンピック」.
• Related朱夏WrittenWritten, elegant name for summer, from the vermillion color of the five elements; 「夏季」 is the ordinary formal term.
• Related朱炎WrittenWritten word for summer heat or midsummer rather than the season as a division; 「夏季」 is the standard formal term.
• Related炎節WrittenWritten, elegant name for the season of heat; 「夏季」 is the ordinary formal term.
• Antonym冬季とうきNeutralNeutral word for winter, the season opposite 「夏季」 on the calendar.

Use 「夏季」 for summer as one of the four seasons in formal contexts, as in 「夏季休暇」 and 「夏季五輪」. In everyday speech say 「夏」; for a summer period of courses or holidays use 「夏期」, for business or weather talk 「夏場」. 「朱夏」 and 「九夏」 are literary names; 「冬季」 is the opposite season.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 【かき・なつき】夏なつの季節きせつ。天候てんこうが暑あつい時期じき。
2. 【かき】一いち年ねんをおおまかに4つに分わけたときの一ひとつで暑あつい頃ころ、およびその前後ぜんご。
3. 【なつき】奉公ほうこうの期限きげんで、春はるの出替でがわりから秋あきの出替でがわりまでの半期はんき。