Hair is hygroscopic — it absorbs moisture from the air. On humid days water molecules slip into the strand and make it swell and bend, lifting the cuticle and breaking the smooth surface. The result is frizz and lost definition.

It varies by hair type, but frizz risk climbs noticeably once relative humidity passes roughly 60–70%. Curly, wavy, colour-treated and high-porosity hair tends to react sooner. The forecast above weighs today's humidity against your hair type.

Seal the cuticle and add a barrier: dry on low heat, press rather than rub with a microfibre towel, smooth in a leave-in or anti-humidity cream while damp, finish on a cool shot, and avoid re-touching once styled. The tool builds a short plan based on your risk.

Only in your browser. If you allow location, your device fetches local weather directly and we use it to estimate humidity. Your coordinates are not sent to or stored on our servers. You can also set humidity manually instead.