In season adverb phrase
Used to describe the point in the year when fruits and vegetables are available and ready to be harvested in large amounts
The prices of vegetables that are in season will be much cheaper.
You should buy fruits that are in season because it is much fresher.
Used to describe the period in the year that it is legal to hunt or catch the animal being discussed.
Check out carefully what's in season before going hunting otherwise you can get a fine.
You cannot catch these birds. They are not in season.
In an animal's breeding period
I usually go fishing when salmon is in season in Alaska.
To be operable or functional.
Be achieved and obtained very easily by someone
To appear or to become available for purchase.
1. To make someone or something become available
2. To become available
To be readily available.