Fresh uncooked ham needs to be baked at 325 degrees F or higher and cooked for anywhere between five and 40 minutes, states What's Cooking America. Exact cooking times vary based on weight, the presence of bones and other factors.
Cooking time must be sufficient for the meat's internal temperature to reach at least 160 degrees F for cook-before-eating ham. Some hams are sold fully cooked and can be served cold. When serving a precooked ham warm, the meat should be reheated in an oven set to 325 degrees F or higher. Fully cooked hams only need to reach an internal temperature of 140 degrees F or higher.