Blow drying your hair in your dream signifies that you are not getting enough time to care for yourself. You are doing too much and you need some fresh air, time with friends and family, or just some me-time to take care of yourself.
On the other hand, if your hair is wet while you are blow drying it, then it could indicate that you have some regrets about your past decisions or things that have happened in life. You might be feeling like you should have done things differently and maybe regret the choices that you made.
Dreaming of blow dry means getting rid of annoyances. Something may be stalling your relationships, and it is time to examine the relationships to put closure on whatever is creating small rifts.
A blow dry also means you want to feel fresh and nice before taking on new opportunities. Always be prepared for what comes your way.