Standard chicken wire will NOT keep weasels out (or much of anything else, because it's so light). Weasels can fit through gaps as small as 1", which is the spacing of poultry wire. You'd be better off with 1/2" or 3/4" hardware cloth.
I would even try to go with something smaller that 1/2 in. hardware cloth... Weasels can collapse their skulls to fit through the tiniest spots that you wouldn't even think of. Also bury the wire so they will have to dig quite a bit to get under.
I would recommend cyclone fencing, or fencing that has barbed wire sticking out. Remember to put netting on top of the fence so predators cannot get in or have chickens escape. Also have an initial fence then a secondary fence to provide two layers of security.
Chicken wire would be your best option. Since weasels can climb and dig you are going to need to bury it deeply with cement at the bottom and then make an encased cage with a roof also made of chicken wire.
I live in King City, Ontario Canada, which is close to Nobelton, and i want to know if there are many weasels here because I just biuld a fence to keep them out, I just want to know if there are many around here, are there?