How does humidity typically affect permed hair?

Humidity typically affects permed hair by causing it to frizz. This occurs because the moisture in the air can interact with the hair, leading to swelling of the hair shaft and disrupting the bonds formed during the perming process. As these bonds are affected by the increased moisture, the hair may lose its defined curl pattern, resulting in a frizzy appearance.

The structure of the hair can also change in humid conditions, as water molecules can penetrate the hair strands and temporarily alter their shape and texture. The excess moisture may cause the outer layer of the hair, known as the cuticle, to lift, allowing for more volume and an uncontrolled look, commonly referred to as frizz. Therefore, understanding the effects of humidity is crucial for maintaining well-defined curls after a perm.