The water temperature at the surface of the western end of the Sound today is 41.1 degrees F. The water holds almost 10 milligrams of dissolved oxygen per liter, which is almost saturated.
In the eastern Sound, the water temperature is 42.8 degrees F, and dissolved oxygen concentrations are higher – 10.7 milligrams per liter.
I get seasick so easily that I wouldn’t go out on the Sound in winter for money, and even if I did, I’d have no idea how to accurately get that kind of data. But no matter. UConn does it, and puts it online. Check it out if you're not familiar with it -- it's fascinating even if, like me, you have no particular use for the information.