Safe to delete /private/var/tmp/*? In this folder, there are 14GB of archives with names such as WiFiDiagnostics follow by a date. Is it safe to delete these archives? A reboot did not remove them.
WiFiDiagnostics* sounds like something you can delete without impact. There are other things in /private/var/tmp which probably shouldn't get deleted (e.g. filesystemui.socket) so rm * is not advisable.