Wild Fires by Julie Trettel

Ryan Davenport is Mayor of Ravenden. He’s a type A personality who likes things neat and orderly. He runs a tight ship and will do whatever it takes to keep Ravenden and those he cares about safe.
But Gracie Montgomery doesn’t make that easy. She’s a carefree spirit with a death wish because she knows she can’t die, at least not by fire. A rare fire witch known as the phoenix means fire can never really hurt her. This makes her reckless and wild, a danger to those around her.
But with an arsonist loose in Ravenden set on destroying their home, the two must set aside their differences and work together to stop him and save the town from the devastating fires while butting heads every step of the way in this opposites attract true mates romance.