Anonymous wrote:I've gone up to Cape Cod for 39 straight summers - so I have some experience in this area.
We stay in Wellfleet, where there is the bay, ocean, and ponds. Ocean is always cold. Always. Doesn't matter what time of year. Yes, you can wade in and some brave people swim, but it is painful. It can be fun at low tide with the sand bars.
The bay is warmer, but I find it kind of gross - lots of hermit crabs, marine life, etc., which is great for exploring but not so great for swimming. You would need to wear water shoes.
BUT, the fresh water ponds are amazing. That's where we go every single day, and where my kids (and I) learned to swim. They are warm enough for swimming, are calm, and clean. There are 5 or so in Wellfleet alone.
The Cape is an amazing summer destination - enjoy!