Seasonable

adjective

1. Opportune; occurring at an appropriate or suitable time.
2. Appropriate to the current season of the year.

   "The temperature outside was quite seasonable, neither warmer nor colder than I had expected."

3. Ephemeral; lasting for just one season.
4. In season (said of game when it is legal to be hunted and killed).
5. Well-seasoned; matured (e.g. timber).