Burn spots from what, the sun?? The idea that water droplets and strong sun will cause leaf damage is an old gardening wives tale. That's more likely secondary to insect or fungal issues...and like Jim said, they'll be on the ground shortly any way.
so do I need to take action if it's fungal? a few branches have only a few leaves left, and i'm hoping those branches won't dry out or be lost. seems a bit early for fall behavior, but maybe not.
I honestly wouldn't worry about it...it would be an entirely different thing if your leaves looked like that in June instead of September. If you want to do something, discard or burn the leaves as they fall away from the tree...and make sure you don't over water as fewer leaves mean les transpiration which means less water is pulled from the soil which means don't water so much or else![]()