What temperature should a freezer be
1 Keep the refrigerator temperature at or below 40Â° F (4Â° C). 2  The freezer temperature should be 0Â° F (-18Â° C). 3  Check temperatures periodically. 4  Appliance thermometers are the best way of knowing these temperatures and are generally inexpensive. If an appliance thermometer was kept in the freezer, check the temperature when the power comes back on. 2  If the freezer thermometer reads 40Â°F or below, the food is safe and may be refrozen. 3  If a thermometer has not been kept in the freezer, check each package of food to determine its safety.