"The winter is a season."

Translation: O inverno é uma estação.

[julinho_a]

Shouldn't temporada also work here?

[vivisaurus]

Maybe, depending on the context. But as a rule, temporada is any season except the seasons of the year.

[lugosky]

Temporada is s season within a season. Meaning: there are 4 estaçoes do ano, but within those estaçoes you might have hunting temporada.

[deguo]

What's wrong with época?

[AutumnAkin1]

Epoca is more like an era

[deguo]

It's funny: I wrote this so long ago that seeing it again now, I'm thinking, "Wow, did I ever think that?!"