The temperature at which a turkey is fully cooked and safe to eat is 165 degrees Fahrenheit (74 degrees Celsius) . To check if the turkey has reached this temperature, use a meat thermometer to measure the internal temperature of the turkey. Insert the thermometer into the thickest part of the turkey, such as the thigh, without touching the bone. Hold the thermometer still until the numbers stop increasing. If the temperature is not yet at 165 degrees Fahrenheit, return the turkey to the oven and continue cooking, checking the temperature at regular intervals. It is important to ensure that the turkey reaches this temperature to avoid the risk of foodborne illness.