Generally speaking, yes it is safe to swim in the Lake District. But as always, do your due diligence: Check current and upcoming weather conditions Let someone know of your expected route and also a return time Ensure you're highly visible with something like a tow float Make sure you have the all the necessary equipment and apparel suitable for the lake and conditions. That can include an insulative swim suit, swimming cap or bobble hat, gloves, and maybe something like a dry robe to warm up in when you leave the water. Be sure to also read our safety guidelines at the top of this post.