Why Your Oven Temperature Is Wrong, and How to Fix It

Most folks just trust their oven to turn on to the right temperature. But regardless of whether or not you have a newer or older model, not all ovens predictably run at an accurate temperature. 

If your oven runs too hot, it can cook the food too fast, or worse, burn the outside while leaving the inside of your food raw. If your oven is running too low, it takes more time to cook the food, which can affect the texture—cakes rising slower and resulting in a dense crumb, or holiday roast taking longer to cook and making a special dinner late. 

These issues can easily be prevented with one small gadget. That’s why I always recommend buying and using a secondary oven thermometer.

Most Ovens Don’t Stay at a Constant Temperature

Depending on your oven, the heating elements are at the bottom (most common), the top (for broiling) or back (for European convection). There’s also an internal thermometer that reads the temperature of the air in the oven. 

When you turn the oven on and set it to the temperature you want, the heating element turns on. Then, once the oven reaches the programmed temperature, the internal thermometer tells the oven to turn the heating element off. When the temperature drops below a certain point, the heating element turns back on. So, despite our impression that ovens hit the desired temperature (like 350°F) and stay there, most ovens tend to fluctuate above and below the temperature you select as they try to achieve an average.

Why You Need An Extra Oven Thermometer

Secondary oven thermometers are more accurate than the built-in oven thermometers, as their sole purpose is just to tell temperature. There are two common types of secondary oven thermometers. 

Analog dial: You leave this thermometer in the oven as you use it. It’s less reactive and takes longer to register the temperature. Choose an analog thermometer that has big, easy to read numbers, as the inside of an oven can be a dark place. I like the OXO one, which is reasonably priced and can hang from the rack or stand on it, depending on what you prefer.

External digital probe: This is more expensive but allows you to read the temperature without opening the oven door (and letting out heat in the process). I prefer this type for convenience and real time accuracy. You place the main unit with the readout outside of the oven, either on a nearby table or magnetically attached to the oven door. Then you use a clip on the oven rack and attach a wired probe that connects the inside of the oven to the main unit. Digital thermometers are more reactive, giving you real time readings as the oven fluctuates, and allowing you to see the temperature of the oven without having to open the oven door.

A fancy digital thermometer that I like is the Thermoworks Square DOT, which has two readings: one to take the temperature of the oven, and another to read the internal temperature of whatever you’re cooking (such as a turkey or prime rib). The DOT even has an option to take the “average” temperature of the internal oven over a 15-minute period, which is convenient for longer roasts. 

How to Fix Your Oven’s Temperature

Once you have the reading from your secondary thermometer, you can adjust your oven temperature accordingly. 

Some newer oven models will allow you to manually calibrate the oven temperature in the control settings. So, if you set your oven thermometer at 350°F but your secondary thermometer is reading at 355°F, you might be able to calibrate your oven down five degrees, making it so setting the oven to 350°F will actually heat to 350°F. Check the manual for details. 

If your oven doesn’t allow you to recalibrate the temperature in the settings, you can always just set your oven to 345°F, knowing that your oven runs 5°F hotter.

The better you know how your oven runs, the better chance you have at being successful in the kitchen. A simple tool like an oven thermometer can solve a lot of your baking and cooking issues.