The seventh 節気 “sekki” division of the traditional Japanese calendar is:
立夏
(りっか)
“rikka”
‘beginning of summer’ // ‘first day of summer’ (solar term)
The first “kō” microseason within this division is:
蛙始鳴
(かわず はじめて なく)
“kawazu hajimete naku”
Frogs start singing
That makes 蛙始鳴 the nineteenth microseason of the year!
It typically lasts 5~9 May.
蛙
(かわず), (かいる)
“kawazu”, “kairu”
frog
始め
(あじめ)
“hajime”
beginning, start, outset
鳴く
(なく)
“naku”
to sing (bird), to make sound (animal), to call, to cry, to chirp
蛙鳴
(あめい)
“amei”
frog calling
Click here to learn about this subseries
Image credit: New York I Love You Kermit Version which is used in one of my favourite mash ups ever.