Number one is always SUNSCREEN. Now we can move on.
One often likes to have a lighter weight moisturizer in the warm months. Even those with very dry skin can feel too heavy with the usual rich creams so lighten up! Your usual brand will most likely have a lighter product available. Try it, you may like it!
How about trying a spritz product in the summer months. Spritzing is always cooling and hydrating. You can spritz directly on to your skin or try a spritz under your moisturizer and see how far it spreads.