Mine will stay in the yard when it does not rain hard and don't even seem to notice it. The one time I had them out when it was pouring rain they went behind a thick hedge of junipers by the back of the house and dustbathed there where it was dry and sheltered......Where in WI are you that you have rain....send some, I'm just west of Madison....
I don't think they really like the rain, at least not a heavy rain. If it's just a soft light rain my chickens will stay out and hunt bugs and seem to enjoy it. Other times they will run to the coop as soon the rain really starts to come down. I have a Banty Cochin that will hall freathers to the coop at the first drop of rain.
If its a heavy rain they run for the coop most of the time. Some of the younger ones don't make it into the coop because one of my BR pullets likes to lay just inside the pop door so she can see when the rain stops and she won't let the younger ones in.
If it's not a real bad rain I just let them work things out for themselves. Sooner or later my BR will let them in. If its a hard rain and I see the younger ones not able to get into the coop I will go out and move my BR from the door way. I have got to make another pop door on the other side of the coop.
Anyway, I think some chickens like the rain to a point and others do not, just like any other critter.
Animals don't have this phobia of weather like people do. My horses can frequently be found grazing unconcerned in a rain or light thunderstorm and the chickens don't care unless it's pouring. It does no harm to get wet for either you or them so long as it's not real cold out. A light rain is great when putting up fence in the middle of summer. Yes you get soaked but you don't cook to death.
People have such issues just walking outside in the rain much less doing work outside even when it's not cold or raining that hard. I fail to understand it.
Mine LOVE the rain. They love it even more when it stops and the ground is soft. They make dirt baths and eat the bugs that came out during the rain. They love it!