Gray and white dwarf hamster in blue cage

I lost my gray and white dwarf hamster yesterday around 3pm. He was last seen near the West Side Market on West 25th Street in Cleveland, after I stepped out to grab a snack and left his blue plastic cage on the front stoop; the lid is a bit loose, so I think he slipped out. He has a white belly, a tiny black dot on his left ear, and a faint copper patch behind the right ear. His name is Niko, and he’s been with me for over a year. I’m really worried and would be grateful to anyone who spots him and lets me know.