Put up the hair dryer for the summer. You're just going to sweat to death while you use it anyway. Hang it up and let it stay there until fall. I suggest turning on the fan in your room while you get ready. Let your hair catch some fresh air for the summer and air dry it. Humidity causes frizz; adding more heat to it from your hair dryer isn't going to help. I also scrunch my hair while on my way to work with the AC cranked and the windows cracked. You may chuckle at this, but I get the most compliments on my own hair when I have done nothing but let it do its thing that particular day. This will be true for you too, I promise.
You do need to get some great products for your hair to help prevent frizz and provide your hair with proper hydration. It may be humid out, leaving you to think you don't need more of it in your hair, but in fact you do. Hair needs proper moisture balance, and in the summer it needs extra love and protection. The summer sun, heat and humidity all take a toll on our hair. Along with regular trims with your stylist, a good product will make a big difference. Paul Mitchell released a SUN line last year that is sulfate free, protects your hair from the sun, adds protein and leaves it looking its best all summer.
If you have any type of texture in your hair, don't fight it. Go with it. Use a great styling product like mousse or gel and scrunch away. The more you fight natural texture, the worse your hair is going to look. Embrace your texture: those that don't have it wish that they did. Summer is a great time to sport loose, messy beach hair and simple styles that are pulled back and kept in place for the day. I can't urge you enough to just go with it and let your hair win. If you start with the right products, I am sure it will stay looking its best.
If all else fails it's just too hot to think about it, I suggest throwing your hair up. A messy top knot, simple ponytail or a braid will do the trick and leave you looking great and right on trend.
If you're still having a hard time with your hair, make sure you talk with your stylist about it. Ask for a summer styling lesson at your next visit or schedule a consultation. Don't stress about it and enjoy the summer - it's almost over!