Your refrigerator temperature should be 40 F or less, and your freezer should be 0 F or less. The best place to put a thermometer is in the warmest spot – which would be near the door, not tucked away in the back. Glance at this daily to be sure it is maintaining a cold temperature.Click to see full answer. Just so, where should a fridge thermometer be placed?We suggest you place your thermometer below the top shelf and towards the door to give a general indication of the fridge temperature. If it shows your fridge is higher than 5°C, adjust the fridge setting to lower the temperature.Secondly, how long does it take for refrigerator thermometer? Put the thermometer in a glass of water and place in the middle of the refrigerator. Wait 5 to 8 hours. If the temperature is not 38 to 40 °F, adjust the refrigerator temperature control. Check again after 5 to 8 hours. Thereof, how can I check the temperature of my fridge? To check the temperature of a refrigerator, it’s best to use food or liquid that has been in the compartment for at least 24 hours. The most common practice is to place a glass of water in the refrigerator (but not in the door) and let it sit for a day. Then place the thermometer in the glass to get a reading.Which part of the fridge is the warmest?The door. This is the warmest area of the fridge as room-temperature air gushes in every time the door is opened. Put your least perishable items on the door, like ketchup, mustard, soy sauce and other condiments with longer shelf lives.