A method for operating a memory device includes: receiving a program command, a memory address, and a program data from a controller; performing a first temperature sensing operation for measuring an internal temperature to produce a first result of the first temperature sensing operation; performing a program operation on the program data based on the first result of the first temperature sensing operation; performing a second temperature sensing operation for measuring an internal temperature to produce a first result of the second temperature sensing operation; and performing a temperature comparison operation for deciding whether the program operation failed when a difference between the first result of the first temperature sensing operation and the first result of the second temperature sensing operation is greater than or equal to a threshold value.