Why dairy cows only in the north?

I think that instead of correlating temperature to dairy farms, you should try to correlate water availability to dairy farms. Here in Wisconsin, we don’t have any water shortages. We use it for anything and everything. There are no restrictions on use, there is no buying water shares. Dairy farming takes alot of water. Milk is about 88 percent water. It takes even more water to clean and sanitize your milking parlor and cool your milk tank and all the other stuff you have to do when you havce a dairy herd. In Utah, where they used to range alot of beef cattle, they hade to provide extra forage and buy water to put in the water tanks for the cows. That would be a very pricey way to make milk.