A storage device includes nonvolatile memories each including an internal temperature sensor; a memory controller configured having a plurality of operation commands defined for different temperature and an external temperature sensor. The memory controller obtains an external temperature value from the external temperature sensor in a first cycle, obtains an internal temperature value of the internal temperature sensor in a second cycle different from the first cycle, determines a temperature range of a target nonvolatile memory based on the external temperature value when a difference between the external temperature value and the internal temperature value is equal to or less than a first threshold value, to determine the temperature range based on the internal temperature value when the difference exceeds the first threshold, and to provide an operation command corresponding to the temperature range to the target nonvolatile memory.