Methods of operating a number of memory devices are disclosed. A method may include receiving, at each of a number of memory devices, a refresh command. The method may also include refreshing, at each of the number of memory devices and in response to the refresh command, a number of memory cells based on a count of an associated refresh address counter, wherein a count of a refresh address counter of at least one memory device of the number of memory devices is offset from a count of a refresh address counter of at least one other memory device of the number of memory devices. Related systems and memory modules are also described.