Josaphine32, if it is any consolation, my dad came across a kitten yesterday (well less than one year old) that a neighbour of his had found earlier in the week, and had apparently gotten scared because of the fireworks and couldn't find her way home.
He is looking after the little cat now and has phoned around local vets, etc to say he has her if anyone asks. The cat has a collar with a bell on it (they've temporrarily called her Bella!) but no contact details, so maybe your little fella is being looked after by someone too.
Cats can be so mean! They make you worry so much, but instead of getting told off they get extra love! I am coming back as a cat without a doubt