is your cat possibly in heat? female cats in heat may do this as well as un neutered males that want to mate. sick cats may also do this.

my female cat started crying at night when she started to age, but she was about fifteen at the time. I know they are night creatures & start to roam at night, you could try feeding late at night before you go to sleep, and leave out dry food also. Hope this helps

if its a girl shes in heat. she wont go out until shes spayed or pregnant