The Right Temperature Settings for Your Refrigerator and Freezer

Set Your Refrigerator to 37–40°F and Your Freezer to 0°F or Below

The refrigerator compartment should stay between 37 and 40 degrees Fahrenheit. The freezer should be at 0°F or colder. These are the temperatures the U.S. Food and Drug Administration recommends to slow bacterial growth and keep food safe. Most refrigerators have a dial or digital display that lets you adjust these independently, so you can set each zone correctly without guessing.

Why these specific numbers? At 40°F, harmful bacteria like Listeria and Salmonella multiply slowly enough that food stays safe for the time you normally keep it. Below 0°F, bacteria and mold stop growing altogether, which is why frozen food lasts for months. If your fridge runs warmer than 40°F, bacteria can double every 20 minutes. If your freezer creeps above 0°F, ice crystals melt and refreeze, breaking down texture and flavor.

The temperature inside your fridge and freezer is not uniform. The back wall is usually coldest, the door is warmest, and shelves in the middle fall somewhere between. Knowing this helps you store food safely: keep eggs and dairy on a middle shelf, not the door; store raw meat on the lowest shelf so it cannot drip onto other foods; and keep frozen items toward the back where the coldest air settles.

Key Takeaways

• Your refrigerator should read 37–40°F and your freezer should read 0°F or colder to prevent bacterial growth and food spoilage.
• Check the actual temperature with a separate thermometer because the dial setting does not always match the real temperature inside.
• The back of the fridge and freezer is coldest, the door is warmest, and you should store different foods accordingly.
• If your fridge runs above 40°F for more than two hours, bacteria can multiply to unsafe levels and food should be discarded.
• Adjusting the temperature dial by one notch can take 24 hours to reach the new setting, so make small changes and wait before adjusting again.

How to Check Your Actual Temperature

The dial or display on your refrigerator is a guide, not a may provide. Many refrigerators run warmer or colder than the setting shows. The only way to know the real temperature is to place a separate thermometer inside and read it after 24 hours. Use an inexpensive dial thermometer or a digital one—both cost under $10 and are sold at grocery stores and hardware retailers.

Put the thermometer in the middle of the fridge, away from the back wall and the door, because that is where food normally sits. Leave it there overnight so it reaches the actual air temperature, not just the temperature of the shelf. Check it the next morning. If it reads above 40°F, turn the dial toward the coldest setting and wait another 24 hours before checking again. If it reads below 37°F, turn the dial slightly warmer.

Do the same for your freezer. Place a thermometer in the center, leave it overnight, and check it the next day. If it reads above 0°F, adjust the dial toward colder and wait 24 hours. Most refrigerators take a full day to stabilize after you change the setting, so resist the urge to keep adjusting. Small changes compound, and you can overshoot easily.

Why Temperature Matters for Food Safety

Bacteria that cause food poisoning—Salmonella, E. coli, Listeria, and Staphylococcus aureus—grow fastest in the "danger zone" between 40°F and 140°F. At 37°F, they slow down dramatically. At 0°F, they stop growing but do not die. This is why your refrigerator buys you time to eat food before it spoils, and your freezer lets you store food for months without it becoming unsafe.

Perishable foods like raw meat, poultry, seafood, eggs, and dairy should never sit at room temperature for more than two hours. If the room is above 90°F, that window shrinks to one hour. Once you put these foods in the fridge at 37–40°F, you have days or weeks depending on the food. Once you freeze them at 0°F or below, you have months. If your fridge warms up during a power outage or malfunction, bacteria can reach unsafe levels in as little as four hours, and the food should be thrown away if the temperature rose above 40°F for more than two hours.

Temperature also affects how fast food loses quality. Freezer burn happens when ice crystals form and break down the cell structure of food. This is not a safety issue—freezer-burned food is still safe to eat—but it changes texture and flavor. Keeping your freezer at 0°F or colder slows this process. Keeping your fridge at the cooler end of the safe range (37°F rather than 40°F) extends the life of fresh produce and dairy by a few days.

Adjusting Your Refrigerator and Freezer Separately

Most modern refrigerators have separate controls for the fridge and freezer compartments. Look for a dial, slider, or digital panel inside the fridge or on the front. Some models have one control that adjusts both, with a damper that directs more or less cold air to each section. Read your manual to find out which type you have—the manual is usually in the drawer under the crisper or available online by searching your model number and "manual".

If your refrigerator has separate controls, start by setting the fridge dial to the middle position and the freezer dial to the middle position. Wait 24 hours, then check both temperatures with a thermometer. Adjust the fridge dial first: if it is too warm, turn it toward colder; if it is too cold, turn it toward warmer. Wait another 24 hours and check again. Once the fridge is correct, adjust the freezer the same way.

If your refrigerator has one control that adjusts both, turning it colder will make both compartments colder. You may need to find a balance where the fridge stays at 37–40°F and the freezer stays at 0°F or below. This usually means setting the dial somewhere in the middle-to-cold range, but every model is different. Check your manual for the recommended starting point, then use a thermometer to fine-tune.

Common Temperature Problems and How to Fix Them

If your fridge is too warm, first check that the vents inside are not blocked. Frozen food, ice buildup, or boxes can stop cold air from flowing into the fridge compartment. Clear any obstructions, wait 24 hours, and check the temperature again. If it is still too warm, turn the dial toward colder and wait another 24 hours. If the fridge is still above 40°F after two adjustments, the compressor or thermostat may need service—contact the manufacturer or a repair technician.

If your fridge is too cold and food is freezing, turn the dial toward warmer. This is common in older refrigerators or models with poor air distribution. A small adjustment usually fixes it. If the fridge keeps freezing food no matter how warm you set the dial, the thermostat may be stuck or the damper may be stuck in the "more cold to fridge" position. Again, this requires professional service.

If your freezer is too warm, check that the freezer door seals properly. Close the door on a dollar bill—if you can pull it out easily, the seal is loose and warm air is leaking in. A loose seal is the most common reason a freezer warms up. If the seal looks intact, turn the freezer dial toward colder and wait 24 hours. If the freezer is still above 0°F, the compressor may be failing and you should have it inspected.

If your freezer is too cold and frost is building up, turn the dial toward warmer. Excess frost usually means the damper is stuck or the thermostat is not working correctly. If adjusting the dial does not help, the refrigerator may need service.

Energy Efficiency and Temperature

Running your fridge and freezer at the recommended temperatures uses less energy than running them colder. Every degree colder increases the compressor's workload. Setting your fridge to 37°F instead of 35°F, or your freezer to 0°F instead of –5°F, saves electricity without sacrificing food safety. Over a year, this can reduce your refrigerator's energy use by 3 to 5 percent.

Other habits also matter. Keep the door closed as much as possible—every time you open it, warm air enters and the compressor has to work harder to cool it back down. Wipe spills and ice buildup off the shelves and vents so air can circulate freely. Make sure the condenser coils on the back or bottom of the refrigerator are clean and dust-free; a dirty coil makes the compressor work harder. Vacuum or brush them every six months.

If you have an older refrigerator that is more than 15 years old, it may use twice as much energy as a new one, even if it is running at the correct temperature. Replacing it with an ENERGY STAR model can cut your refrigerator's energy use in half. The upfront cost is higher, but the savings on your electric bill usually pay for it within five to seven years.

Frequently Asked Questions

What should I do if my power goes out?

Keep the refrigerator and freezer doors closed. A full freezer will stay safe for about 48 hours if unopened; a half-full freezer for about 24 hours. A full fridge will stay safe for about 4 hours. After the power comes back on, check the temperature with a thermometer. If the fridge was above 40°F for more than two hours, throw away perishable foods like meat, dairy, and leftovers. Frozen food that still has ice crystals is safe to eat or refreeze.

Can I set my fridge colder to make it cool faster?

No. Setting the dial colder does not speed up cooling—it just makes the fridge colder than necessary. The compressor runs until the fridge reaches the temperature you set, then it cycles on and off to maintain it. A colder fridge uses more energy and can freeze your food. Set it to 37–40°F and let it work normally.

Is it okay to store leftovers in the fridge door?

No. The door is the warmest part of the fridge because it opens to room temperature every time you use it. Store leftovers, raw meat, eggs, and dairy on the middle shelves where the temperature is more stable. Use the door for condiments, butter, and other items that tolerate warmer temperatures.

How long can I keep food in the freezer?

Frozen food is safe indefinitely at 0°F or below, but quality declines over time. Ground meat and poultry last 3 to 4 months; steaks and chops last 6 to 12 months; whole chickens last 12 months; and fatty fish lasts 2 to 3 months. Vegetables last 8 to 12 months; fruits last 8 to 12 months. Label everything with the date you froze it so you know how long it has been there.

Why is my freezer icing up?

Frost and ice buildup usually means the door seal is loose, warm air is leaking in, or the defrost drain is clogged. Check that the door closes firmly and the seal is not cracked. If the seal is fine, the defrost drain (usually a small hole at the back or bottom of the fridge) may be blocked by food particles or ice. Thaw it with warm water or a pipe cleaner. If neither fixes it, the thermostat or damper may need service.