You can prevent frizzy hair in humidity by moisturizing your hair really well, not heat-styling your hair, and using an anti-frizz product to hold the hair in place. Keeping the hair well moisturized is key to stopping excessive frizz because dry, damaged hair is prone to frizzing. Along the same lines, you should reduce the amount of heat-styling you do because of how much moisture it takes from your hair in addition to how damaging it can be. Lastly, an anti-frizz product is a holding product that acts like hair spray, but it is usually applied on damp hair and let to dry before exposing the hair to humidity.
It might seem counter-intuitive, but moisturizing your hair helps prevent frizzy hair in humidity. Use a gentle shampoo at night followed by a good rinse-out moisturizer. Deep condition your hair once a week for at least 30 minutes and wear a light leave-in conditioner during the day. If you have problems with greasy roots, start conditioning the hair halfway down and ending at the tips, which is the most fragile part of anyone’s hair. Starting halfway down instead of at the roots ensures that the top part of your hair, which is the healthiest and most naturally moisturized by scalp oils, does not become greasy during the day.
Stop heat-styling your hair during the summer to prevent frizzy hair in humidity. Heat-styling is damaging to hair, and damaged hair is more prone to frizzing. Using hot tools on hair also steams the moisture out of it, leaving you with drier, even more frizz-prone hair. In addition, frizzy hair is more noticeable on bone-straight styles. If your hair is naturally wavy or curly, do without the heat-styling tools and try a side ponytail or braid.
When all else fails, use an anti-frizz product to prevent frizzy hair in humidity. There are many such products, but they are usually meant to be applied to wet or damp hair. Once the hair dries, the serum or gel acts like hair spray to keep all the strands in place. In fact, hair spray can also work to prevent frizzy hair in humidity, though usually not as well as following the instructions on an anti-frizz product. As with most other holding hair products, you should not expect the product to work throughout the entire day, especially if the humidity is far above average.