What Temperature Should My Freezer Be?

Fridge freezer temperature display settings showing -18°C for freezer and 3°C for fridge

Learn all about the ideal temperature of a freezer.

In this guide, we’ll look into freezer temperature. The main question we’ll be answering is what temperature should freezers operate at? It’s sometimes obvious when your freezer isn’t cold enough; your food isn’t completely frozen or your ice cream is melted. But how can you tell if it’s too cold? Is that even possible?

We’ll also discuss why there’s a recommended temperature, and what you can do to ensure it’s maintained.

What is the Ideal Freezer Temperature?

The ideal freezer temperature is -18°C. This may need to be adjusted slightly depending on your environment, however, this is always the best temperature to start with. 

This temperature has been recommended since 1964 by the International Institute of Refrigeration (a real thing). But why -18°C? Can’t it be colder?

It’s true that the colder the freezer temperature, the better your food will keep. For example, a temperature of -30°C would keep food fresher for longer. So why do we not keep our freezers at this temperature?

The main reason for this is because the lower the temperature, the more energy you use. So, if you don’t mind a higher energy bill, then by all means lower your freezer temperature settings. But, you can be rest assured that -18°C has been recommended because it is a happy medium between energy consumption and food quality.

A freezer temperature guide. Summary: -18°C is the recommended freezer temperature for food safety, freshness, and lower energy consumption

Why Should Your Freezer Be at the Right Temperature?

As we’ve just mentioned, -18°C is the perfect freezer temperature because it keeps your food frozen without wasting energy. But other than keeping your energy bill down (which just by itself is reason enough for most), are there any other reasons to keep it at this temperature?

Absolutely! Plenty of research has proven -18°C as the winning temperature. Let’s delve into it.

What happens when the freezer temperature is set higher than -18°C?

Food can still be frozen when the freezer is set warmer than -18°C. In fact, food will begin to freeze at 0°C (the well-known freezing point). However, food that’s kept frozen between 0°C and -17°C will sacrifice safety and quality.

The colder the temperature of your freezer, the safer it is. That’s because cold temperatures reduce, or even stop, the growth of bacteria. So, although still cold, higher temperatures can allow bacteria to grow. It’s therefore better to lower your freezer to -18°C. At this temperature, bacteria growth is stopped, preventing illness or food spoilage.

Higher temperatures can also affect food quality. There are a couple of reasons for this. Firstly, higher temperatures mean that it takes longer for the food to freeze. The longer it takes to freeze, the bigger the ice crystals that form, which can affect the taste and texture of your food. 

Secondly, fruits, vegetables, and other nutrition-rich foods are more prone to nutrient loss. Therefore, storing these at a lower temperature will help them maintain their freshness and nutritious value.

Ice cream cone on the floor with pink melted ice cream spilling out. Against a solid blue background.

What happens when the freezer is set lower than -18°C?

Other than increasing energy bills, lowering your freezer temperature below -18°C has little negative impact. Food tends to stay fresher at even lower temperatures. However, when it’s too cold, the chances of your food becoming freezer burnt are increased.

There are a few different factors that can cause freezer burn to occur. One of these is your freezer temperature being too cold. The main reason for this is because the cold temperatures increase the rate at which moisture is lost from food. This loss of moisture causes the surface to dry out and lose texture; this is freezer burn.

Lower temperatures can also increase the rate of ice build-up, meaning you will need to defrost your freezer more regularly. Finally, at extremely low temperatures, your freezer may overwork and break.

Lots of berries with frost over them. Potentially with freezer burn


In summary, the lower you can keep your freezer temperature, the safer and more nutritious your food will be. Fast freezing is when your food can rapidly freeze, which locks in nutrients and prevents the formation of large ice crystals. However, maintaining an extremely low temperature over time can lead to an increased chance of freezer burn, ice build-up, and higher energy costs.

By keeping your freezer at the recommended temperature of -18°C your food will remain safe and retain its nutritional value, without increasing your energy bills too much or increasing the risk of freezer burn.

Some freezers offer a “fast freezing” feature. This temporarily decreases the temperature of your freezer, so that your food can freeze even quicker when you first place it in. This gives the added benefit of your food staying fresher and retaining more nutrients, without the need for your freezer to remain at this lower temperature.

A photo edit showing a container filled with oil and a thermometer inside of a freezer. The container is in-between a tub of ice cream and bags of vegetables

How to Check Your Freezer Temperature

Most modern freezers will display your freezer temperature, however, not every freezer has a thermometer built-in. If you don’t have a temperature display, there’s still an easy way of checking the temperature of your freezer.

The easiest way is to buy a dedicated freezer thermometer. Placing this inside of your freezer should give you an accurate result. If you don’t have a freezer thermometer though, you can use a standard thermometer:

  • Fill a small freezer-safe container with cooking oil and place it in your freezer, ideally in between some frozen goods.
  • Put a thermometer in the oil. Leave this overnight, without opening the door.
  • Check the temperature on the thermometer. You should do this the first time the freezer door is opened that day.

This should give you an accurate read of your freezer temperature. You can then adjust accordingly if needed.

How to Maintain Freezer Temperature

Well-built freezers can easily maintain the correct temperature when the correct conditions are met. If these conditions are not met, your freezer may experience fluctuating temperatures or need to work harder to stay cold. The following advice will help your freezer maintain a constant temperature:

1. Don’t overfill your freezer. Air needs to be able to freely move about your freezer. If you overfill it, you will block this airflow, which is what cools it down.

2. Keep your freezer well stocked. Although you don’t want to overload your freezer, you still need to keep it well stocked. The frozen items inside will help to keep the temperature down.

3. Don’t leave the door open for too long. The longer it is left open, the more warm air can enter. Your freezer will also need to work harder to bring the temperature back down.

4. Avoid placing hot or warm food in the freezer. Allow it to cool down first. Otherwise, it will heat the other contents in your freezer.

5. Regularly check your door seals. If cold air is escaping, your freezer will need to work harder to maintain a cold environment.

How to Prevent Freezer Burn

What is freezer burn?

Freezer burn is damage caused by the dehydration and oxidation of the affected food. This damage can result in decolourisation and unpleasant textures. Although the quality of the food is affected, freezer-burned food is still safe to eat. You probably won’t want to though!

What causes freezer burn?

As mentioned above, freezer burn is damage caused by dehydration and oxidation. But what does that mean? Freezer burn is the result of when moisture inside of the food evaporates, drying out the surface. This is more likely to happen to foods with higher moisture content, such as fruits or ice cream.

Freezer burn can happen over time regardless of how well it is frozen, however, certain practices can dramatically accelerate the process. To avoid this, follow the directions below when freezing your foods:

  • Tightly wrap food in airtight packaging. Exposure to the cold, dry air of the freezer can rapidly increase the chances of freezer burn. Therefore, you’ll want to carefully wrap everything you put in the freezer. Try to remove as much air as possible from the inside of the packaging too. The less air that has access to the food the better!
  • Avoid opening the freezer door too often. Whenever you open the freezer door, you allow warm air to enter. This causes a sudden fluctuation in internal temperature, which can lead to freezer burn.
  • Avoid Refreezing Food. The chance of freezer burn increases each time you thaw and then refreeze food. It’s therefore best to avoid refreezing as much as possible by only thawing the amount of food you know you will eat. Freezing in smaller batches can help you achieve this.
  • Keep your freezer at the ideal temperature. When too cold, the process that causes freezer burn speeds up. When too warm, larger ice crystals form as your food freezes, increasing the risk of freezer burn.
Opened bag of frozen vegetables that have been affected by freezer burn