Refers to the middle of summer, often used in literary or poetic contexts. In modern Japanese, 真夏 (まなつ) is more common for everyday use.
In this midsummer season, I hope you are all doing well.
fifth month of the lunar calendar
Obsolete term for the fifth month of the old lunar calendar, roughly corresponding to June. Cross-referenced with 皐月 (さつき), which is the more common name for that month.
See also: 皐月
In the old lunar calendar, 仲夏 corresponds to the month of Satsuki.