Keep oven-baked salmon moist by thawing before cooking, marinating the fish, including a pan of water and baking it according to the minimum cook time. Overcooking a salmon fillet quickly dries out the fish.
Frozen salmon takes longer to cook through the middle. By the time the middle is ready, the outside becomes dry and overcooked. Thawing salmon in the refrigerator or in a bowl of cold water allows the fish to cook more evenly.
A marinade or sauce adds moisture before baking. For example, lemon pairs well with salmon, so cooks sometimes use lemon juice in their marinades. An alternative to a sauce is a thin layer of olive oil or a splash of lemon juice topped with seasonings.
The cooking time is one of the biggest factors when it comes to the moisture level of baked salmon. The salmon fillet pulls apart easily when done. Contrary to popular belief, if the salmon flakes easily, it has overcooked.