A memory system includes a nonvolatile memory that includes a plurality of regions; a volatile memory; and a controller that is connected to the nonvolatile memory and the volatile memory. The controller is configured to store in the volatile memory a plurality of first counter values each indicating the number of times each of the plurality of regions has been accessed and a plurality of second counter values respectively corresponding to the plurality of first counter values, and write the first counter value of a first region of the plurality of regions to the nonvolatile memory in response to the second counter value of the first region being equal to or more than a threshold value.