Blight

I have vegetables in containers on the deck - tomatoes and squash came from Wal-Mart and Whole Foods. Several plants have blight. I'm not sure if its the infamous Wal-Mart blight or not, because I notice that nearby trees seem to have some kind of blight also. By "blight" on the trees and tomatoes, I mean that several leaves are yellow and have dark brown "decay" spots on them. The "blight" on the squash leaves starts with an ashy gray-white covering of the leaf, followed by its withering into brown.

Colorado Springs has experienced a large amount of rain this summer. A large number of my tomato plants have stunted growth and yellowing leaves with spots. Plants in containers seem to be doing fine but the plants in my raised garden are not. Is this a drainage problem or a temperature problem?