The ideal temperature for a refrigerator is 37°F (2.8°C) . The U.S. Food and Drug Administration (FDA) also recommends that the refrigerator temperature should be at or below 40°F (4.4°C) . Keeping the temperature at or below 40°F (4.4°C) inhibits the growth of microorganisms that can cause foodborne illnesses, such as salmonella, listeria, and E. coli. However, setting the temperature to 37°F (2.8°C) will keep fresh food good for as long as possible, with no ice crystals on lettuce or bacteria breeding in raw meats.

Its important to note that the temperature controls on many refrigerators only allow you to choose from a series of numbers, usually 1 through 5, with 1 being the coldest and 5 being the warmest. Even when refrigerators have digital controls for setting precise temperatures, the settings aren’t always accurate. Therefore, its recommended to use a refrigerator thermometer to ensure that the temperature is at the desired level.