OK, when do most people shut down the pool for winter? Obviously, when it's too cold for you to be comfortable swimming, but what I'm really asking is, is there a known temp range that most people agree is too cold for comfort and begin to close the pool for winter?
Personal preference. My brother-in-law lives in Ohio and his pool water rarely gets out of the lower to mid 80s all summer, so they often swim when the water temp is in the lower-mid 70s. Here in South Carolina I personally don't get into the pool unless the water temp is at least mid 80s. To me, 88-92 is just about perfect. Also, here in SC a lot of people don't even "close" their pools, they just adjust the amount of time their pumps run and how often they have to add chlorine and keep it "open" (but not swimming in it unless it's "heated") all year. In my part of the state it doesn't cold enough to freeze the pipes in your house, let alone in a pool that you could leave running 24/7 during freezing temps if you needed to.