Why does my hair curl more when it is humid?

Question

I have fairly curly hair, and I know that when it is muggy out my hair gets much curlier. Can anyone explain to me why and how the water vapor in the air can do this?

Answer 1

Hair can absorb moisture very efficiently.That is why the human hair is used as a sensor for measuring humidity in hygrograph.So when the hair absorbs the moisture,it becomes more flexible and tries to attain its original shape.In fact its length increases by 2.5 percent if relative humidity reaches 100 percent.In your case your hair's original shape is curliness.So it tries to attain that shape and becomes more curlier.

It may be noted that the hair is affected only by moisture and not by other weather elements like temperature.

Answer 2

because the water from the water vapor in the air absorbs into your hair follicles and the moisture makes your hair fluffy or curly.  Try using garnier fructis sleek serum, comes in a little round clear bottle. it's AMAZING.

Answer 3

i THINK when it gets hot, it just "comes up" and WALAH! Curly!!

That happens to me. I have VERY VERY curly hair but, after it gets wet, it stays wavy(i also have VERRYY wavy hair, lol, us europeans =3) until it gets hot. then, it gets staticy and curly

Answer 4

There is a long answer and a short answere for this question.

First, the short answer:

Here's the hair basics.  Straight hair tends to be more oily and curly hair tends to be more dry.  People with straight hair have lots of problems with 'oily hair' and people with curly hair have problems with dryness.  So, when there is moisture in the air, for example increased humidity of summer, the dry hair seeks to soak up the moisture.  This causes the cuticle of the hair to expand and the 'frizz'.  Simple!

Now, the long answer, aka cell biology:

First, think about how hair is made and how it's held together.. A strand of hair is made up of invisibly small molecules, primarily made up of a  protein called "cytokeratin". These molecules bond to each other, kind of like holding hands or being held

together by Velcro. There are two main kinds of bonds between molecules in a strand of hair that affect how straight or curly it is. One kind is very strong and permanent, kind of like being stapled together. These are bonds

between sulfur atoms. When you get a "permanent" to straighten or to curl your hair, the smelly chemicals that are used have lots of sulfur in them that breaks these bonds and then allows them to re-form in new places. If the hair is set straight when the chemicals are removed, is stays straight.

If it’s set curly it stays curly (until new hair grows out of your head again with your own normal curliness or straightness).

Now, the second kind of bond between hair molecules. These are called"hydrogen bonds", and they’re much weaker and more temporary than the sulfur bonds. If you think of the sulfur bonds as being like staples, then the hydrogen bonds are more like paper clips. The amount of water in the

air affects these bonds. When your hair dries, these hydrogen bonds get set up. If the air is dry, like on a dry day or under a hair drier, your hair will have a certain amount of curliness to it. If the humidity goes higher, then water dissolved in the air goes bouncing around into everything,

including your hair. That is, your hair is absorbing a small amount of water, even though it doesn’t feel wet. The water has a very strong effect on the hydrogen bonds, and allows the "paper clips" to shift around a bit, but it doesn’t affect the permanent sulfur bonds. So the amount of curliness in your hair changes when the humidity goes up. If you have hair

that has the sulfur bonds set for curliness  then your hair will tend to get curlier, or "frizzier", when the

hydrogen bonds relax. People with straight hair who curl it with curling irons or rollers or with a brush when they dry it have exactly the opposite experience  - their hair straightens out when it gets more humid, but for exactly the same reason. The hydrogen bonds that set up a temporary curliness get broken, and the sulfur bonds that in their case are set for

straight hair take on their natural shape.

Stay curious!

Answer 5

In very humid weather, there's a lot of moisture. That moisture is taken from your hair, causing your hair to take a need for moisture, so it rises. Also, the moisture can contain nutirents that the hair needs. So that hair will stay in the air until it gets its nutrients and moisture back!

From,

The Weather Freak