Memory system and storage system

A memory system comprising:

• a nonvolatile memory including a plurality of blocks, in each of which a plurality of memory cells is arranged between bit lines and a source line, the plurality of memory cells being arranged in rows and columns and the plurality of memory cells of a same row being connected to the same word line and the plurality of memory cells of a same column being connected to a same bit line;
• and
• a memory controller configured to control an operation of the nonvolatile memory, wherein
• the memory controller is configured to issue a warming command to the nonvolatile memory when a temperature of the nonvolatile memory is lower than a first temperature threshold, and
• the nonvolatile memory, in response to the warming command, performs a warming operation that includes:
• selecting a first block from the plurality of blocks, the first block being a defective block that is an invalid block or a free block that stores no valid data;
• applying a precharging voltage to at least one bit line that is connected to memory cells of the selected first block, the applied precharging voltage being higher than a normal precharging voltage that is applied to a bit line of a normal block at a time of reading data stored in a memory cell connected to the bit line of the normal block,
• causing current to flow through the at least one bit line of the selected first block, the current being derived from charges stored as a result of the precharging voltage being applied to the at least one bit line, and
• applying a read pass voltage to each word line of the selected first block, the read pass voltage causing all memory cells connected to each word line to turn on.