Where I live raccoons and possums are nocturnal unless something is wrong with them.
Rats, mice and voles are of no danger to any of my mature chickens as long as they are awake.
Based on that, my chicken yard is fenced against dogs and coyotes, with 4" or even larger openings.
The hens are in the coop by dusk, and the coop has no openings bigger than 1/2".
When I had a combination coop/run, only the bottom 2 feet of fencing had 1/2" sized openings, just to sure that raccoons couldn't spook them into reach.
The rest was chain link and such, but I wasn't worried about rat sized predators at that time.
I don't have a lot of hawk pressure but If I did I would try wires, chicken wire or snowfencing overhead.
I do have a lot of natural cover for the hens, mostly for shade/food.