in season meaning

• 1. Ripe, fit and ready for use
  2. Available
  3. (eg in the holiday trade) at the busiest time of the year
  4. Allowed to be killed
  5. (of a bitch) ready to mate, on heat
  6. Fit to be eaten
• 
  [American idiom]
  currently available for selling. (Some foods and other things are available only at certain seasons.)
  • Oysters are available in season.
  • Strawberries aren't in season in January.
  • When do strawberries come into season?
  
• 
  [American slang]
  1. [of a game animal] subject to legal hunting.
    You cannot shoot ducks. They are not in season.
  2. [of a female animal] ready to breed; in estrus; in heat.
    The cat's in season again.
  3. to be currently available for selling. (Some foods and other things are available only at certain seasons. Typically: be ~; come [into] ~.)
    Oysters are available in season.
    Strawberries aren't in season in January.

• on-season:    adj., adv.when thi ...
• season:    Noun: season  ...
• in season and out of season:    At all times

Examples

1. strawberries are cheaper when they are in season.
2. grouse will soon be in season again.
3. these are the dog days; watermelons are just in season.
4. strawberries are in season now.
5. it is now late in season and our clients are in dire need of this fertilizer.