In Season: Oysters. Our recipe recommendations for what's in season. Raw, fried, baked, stuffed or made into a sandwich, oysters are always satisfying. The bivalves are available all year, but they're best eaten in the colder months from September to April. While a long-standing myth says oysters should not be eaten during months that do not contain an R (May through August), oysters generally are thin in the summer because they devote their energy to reproducing.