A method for controlling temperature of a memory system which includes a memory device suitable for storing memory map data including a logical address of an external device and a physical address of a memory device, corresponding to the logical address; and a controller suitable for downloading at least a part of the memory map data and storing and managing the downloaded data as controller map data, and uploading at least a part of the controller map data to the external device, the method comprising: measuring temperature of the memory device; and performing a map downloading for the memory map data from the memory device in response to the measured temperature.