Oily skin is most common in summer because the rise in temperatures kicks off excess production of sebum in your sebaceous glands. Why? Because your hair loves you and is trying to overcompensate with production to ensure you see no dryness or flakes. It really has good intentions. But the excess oil can lead to issues like dandruff and irritation. Roll it back by shuffling your washes between a clarifying shampoo that deep cleanses your scalp and an anti-dandruff shampoo that can tackle itchiness and flakes. For a deeper cleanse to remove build-up, you can also try a scalp scrub for that fresh, fresh feeling.