Webster's
Definition of rainThe plural form refers to "the rainy season", as does the definition provided by you in post 117. Which is what I said in post 110 - rains used to be a reference to the rainy season. That usage has been enlarged to include how this article uses it.
- a: water falling in drops condensed from vapor in the atmosphere
b: the descent of this water
c: water that has fallen as rain : rainwater- a: a fall of rain : rainstorm
b: rains plural : the rainy season- rainy weather
- a heavy fall • a rain of arrows