What temperature should my fridge and freezer be?
5°C and -18°C, why the dial number tells you nothing, and where the cold spots are.
- Difficulty
- beginner
- Time
- 10 min
- Read
- 2 min
- Safety
- caution
Short answer
Fridge at 5°C or below, freezer at -18°C. The numbered dial is a setting, not a temperature — a cheap fridge thermometer is the only way to know what yours is actually doing.
Most people set a fridge by turning a dial to a number that means nothing and never check the result. Since the difference between 4°C and 9°C is the difference between safe and not, that is worth two pounds and five minutes.
Safety
Step by step
- Aim for 5°C or below in the fridge.Below 8°C is the safety threshold; 5°C or below gives a margin and keeps food better. Above that, food poisoning bacteria multiply.
- Aim for -18°C in the freezer.The standard. Warmer than that and food deteriorates faster and keeps for less time than the packaging assumes.
- Measure it rather than trusting the dial.A fridge thermometer costs very little. Dial numbers are arbitrary settings that vary between models and tell you nothing about the actual temperature.
- Measure in the middle, over 24 hours.A glass of water on a middle shelf, left overnight, then measure the water. It gives an average rather than a reading taken just after the door opened.
- Know where the cold and warm spots are.The back and bottom are coldest; the door is warmest. Milk on the door is a common mistake — it is the least suitable place for anything that spoils quickly.
- Store things where they belong.Raw meat on the bottom shelf so it cannot drip onto anything, cooked and ready-to-eat food above, salad in the drawers, and only robust things in the door.
- Do not overfill or underfill.A packed fridge blocks airflow and creates warm pockets; a nearly empty one swings more in temperature. Reasonably full with room for air to circulate is right.
- Check the seal and give it space.Close the door on a piece of paper — if it pulls out easily the seal has failed. And leave a gap around the outside so it can shed heat.
Tips
- Check the temperature after a heatwave or if the fridge has been very full. Both push it warmer than usual.
- A fridge thermometer left permanently in place turns this into a glance rather than a project.
- Freezers in unheated garages often fail in winter — many are not rated for low ambient temperatures and stop cycling properly.
Questions people ask
What number should my fridge dial be on?
There is no universal answer — the numbers are settings, not temperatures. Measure with a thermometer and adjust until it reads 5°C or below.
Where is the coldest part of a fridge?
The back and bottom. The door is the warmest, which is why milk and anything that spoils quickly is better on a shelf.