The /var/tmp directory is made available
for programs that require temporary files or directories that are
preserved between system reboots. Therefore, data stored in
/var/tmp is more persistent than data in
/tmp.
Files and directories located in /var/tmp
must not be deleted when the system is booted. Although data stored
in /var/tmp is typically deleted in a
site-specific manner, it is recommended that deletions occur at a less
frequent interval than /tmp.