Kids Gardening Set My Garden Pool Is Set Up In The Back Yard For The Kids - Will It Heat Up Faster With Or Without The Cover On?

My Garden Pool is set up in the back yard for the kids - will it heat up faster with or without the cover on? - kids gardening set

I thought you fill the tank with tap water and the sun shines. I know it takes one or two days to adjust to room temperature, but warm up quickly, with or without blue PVC jacket?