Storage device and operating method thereof

A method of operating a storage device comprising a memory device and a memory controller controlling the memory device, wherein the memory device includes a plurality of memory cells, the method comprising:

• receiving a read request with respect to selected memory cells, among the plurality of memory cells;
• obtaining levels of an offset voltage according to a type of a read operation to be performed among a plurality of read operations by the memory device based on an environment information;
• calculating read voltages to be used for the read operation by applying the offset voltage to default read voltages of the memory device;
• performing the read operation using the read voltages,
• wherein the plurality of read operations include a cache read operation, a short-time read operation, a cross temperature read operation, or a first page read operation.

A memory system comprising:

• a memory device including memory cells;
• a storage storing at least one piece of information representing:
• whether a read operation to be performed is a cache read operation;
• elapsed time after completion of a previous program operation;
• temperature of the memory cells during the previous program operation;
• and
• whether a target memory block of the read operation is an unselected block during a previous operation;
• a read voltage determiner determining a read voltage for the read operation by referring to the information and selectively based on temperature of the memory cells during the read operation;
• and
• a read operation controller controlling the memory device to perform the read operation with the determined read voltage,
• wherein the information is stored in the storage on a basis of physical addresses of the memory cells.