Is it safe to leave the iMac turned off for months at a time?
Is it safe to leave your iMac turned off for months at a time?


Yes, it is perfectly safe to leave your iMac turned off for months, as long you follow the proper storage guidelines, i.e. keep it in a cool and dry place and away from exposure to dust. Specifically, follow the storage guidelines laid out by Apple, as discussed here:


Important handling information for your Mac



  
  Storage temperature: -40° to 116° F (-40° to 47° C)
  Relative humidity: 5% to 95% (noncondensing)
  
  
  Storing your iMac. If you are going to store your iMac for an extended period of time, keep it in a cool location (ideally, 71° F or 22° C).


Storing an iMac unused for an extended period of time won't have any affect on its performance.