The recommended temperature for a freezer is at or below 0°F (-18°C) . This temperature is cold enough to keep food frozen and preserve it until it is ready to be cooked or reheated. The typical factory setting for a freezer is 0°F (-18°C) . However, the temperature may need to be adjusted by a few degrees depending on factors such as the freezers environment, humidity, or outside temperatures. It is important to keep the freezer temperature constant, so it is recommended to place an appliance thermometer in the freezer and check it regularly. Overfilling the freezer can block the internal air vents, making it harder to distribute cold air throughout the freezer, so it is recommended to keep the freezer around 75-80% full. If the power goes out, it is important to keep the freezer door closed as much as possible to maintain the temperature. A freezer can keep food at a safe temperature for around 48 hours if the door remains closed.