The twelfth 節気 “sekki” division of the traditional Japanese calendar is:
‘blistering heat’ // ‘major heat’ (solar term)
The last “kō” microseason within this division is:
(たいう ときどき ふる)
“taiu tokidoki furu”
Great rains sometimes fall
That makes 大雨時行 the thirty-sixth microseason of the year!
It typically lasts 3~7 August.
I couldn’t find たいう as a reading for 大雨 but I suspect it can still be valid in this type of older context. What I found instead was:
However, why wasn’t the repeater のま character (々) used in 時?
“Tokidoki” is one of my favourite Japanese words and the repeater character is one of my favourite quirks of the Japanese language!
Again, I am sure there is a good explanation and it is just that this is an “old style” of writing…