Refers to the act of raining or a period of rain. Often used in weather forecasts and everyday conversation.
It will likely rain tomorrow.
On rainy days, I read books at home.
noun which may take the genitive case particle 'no'
Used attributively with の to describe something associated with rain, such as a day, weather, or season.
The rainy season has arrived.
It's expected to turn rainy in Tokyo from this afternoon.
I like reading at home on rainy days.
The rainy weather has continued all week.