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The use of humectants and knowing the dew point of the day can reflect on what kind of hair day you will have. Understanding them can certainly help lead to more consistent good hair days- something we all want! If you hear the terms “Humectant” and “Dew Points” and are unsure of what they mean or how they relate to your hair, my hopes is this article will help clear that up for you. 

So, what exactly is a humectant?

A humectant absorbs moisture and keeps a moisture balance in the hair and skin. Humectants will search for moisture in your own hair too. Therefore, in areas where it may be hot, but dry, these products may actually do more bad than good. In the right condition, humectantsare materials used in products to moisturize dry or damaged hair.  They promote moisture retention by attracting water molecules from the local environment and binding them to specific sites along their structure.   

A humectant absorbs moisture and keeps a moisture balance in the hair and skin.

Are Humectants Good or Bad?

Both. It completely depends on the situation. Here are 2 situation humectants are not your friend:

  • BAD: In areas where the moisture and humidity is very high, like areas that are wet such as down in Florida for example, combined with the heat of the summer, humectants can overdo their job by absorbing so much moisture that the hair becomes “bloated.” This leads to puffy, frizzy hair, instead of well defined curls and waves. Generally speaking, higher your hair porosity, the more you may suffer from this.
  • BAD: On the opposite end of the spectrum, when there is extremely low humidity conditions, humectants can actually draw water away from the hair shaft causing dryness and breakage! 

So when can a humectant be your hair’s bestie?

  • GOOD: Given the ideal dew point outside, the use of humectants can help hair stay bouncy and retain the curl. Using humectants can also make hair feel softer, more elastic and less brittle and also protect hair from dry weather and wind.

Dew Points

Understanding dew points can be a deciding factor in figuring out when to use humectants and when to avoid them.

The definition of dew point: the temperature at which a vapor (as water”> begins or would begin to condense.

Please note: this is referring to degrees in terms of the dew point, not how hot or cold it is.

Different Dew Point Levels

Dry Dew Point: 15-30 degrees (-1 C”>

  • Typically the winter months.
  • Avoid humectants.
  • Use leave in conditioners.
  • Use light hold products.
  • Use plenty of emollients (moisturizing oils, butters”>.

Mid-Range Dew Point: 30-40 degrees (-1 to 4 C”>

  • In  between seasons, this will require trial and error to see what your hair likes.
  • Some curls tolerate humectants in this range, some don’t.
  • Use emollients.

Best Dew Point for Curls: 40-60 degrees (4 to 16 C”>

  • You will enjoy the best curls at this dew point.
  • Keep your hair moisturized.
  • Humectants can be used.
  • Use emollients.

High Dew Point: 60 (16C “> +

  • May skip a leave in conditioner.
  • Hard hold products like gels. You will want to control your hair.
  • May want to avoid humectants.
  • Use emollients.

We wish there was a magical mathematical formula to tell you exactly which ingredients to use in which temperature and humidity conditions. The best we can do is provide you with some loose recommendations on that topic. As always, you will need to do some experimentation with your own hair to find the combination of conditions and product that give the results you prefer.

If the dew point is below 35°F or so, the moisture content in the air is sufficiently low that a humectant applied to your hair might be irresistibly drawn to the moisture in your hair and make every attempt to steal it from you (by drawing it out of your hair and binding it to itself”>. This can result in dry, fly-away hair, split ends, and broken strands.

This effect can often be compensated for by using plenty of moisturizing products, not over-drying your hair (leave it somewhat moist after washing”>, and layering leave-in conditioners with humectant-containing styling product.

Curly hair seems to really thrive in moderate climactic conditions, and dew point ranges of approximately 35°F to 50°F seem to be optimal. In this type of weather, most curlies find that they can get really pleasant results by using products that contain some humectants. There is just enough moisture in the air that the humectants can grab a little from the environment, which can enhance the curl and create a bouncy feeling to the hair.


When the dew point for your area is at 60°F or above, it might be a good idea to apply some product with anti-humectant properties. These products will seal the hair shaft, flatten the cuticle and prevent atmospheric moisture from absorbing into the interior of your strands. Most of these products will contain ingredients that are water insoluble. However, many of these products contain ingredients which are easily removed with an extremely mild shampoo or perhaps even a thorough conditioner wash.

The key to having the best curls in any weather is to have extremely well-hydrated and moisturized hair. This will protect your hair from losing too much moisture in dry weather, and it will prevent your hair from absorbing excess moisture in humid conditions. Another important factor is the overall condition of your hair. Hair that is damaged will necessarily be more porous, and thus more susceptible to climactic conditions. Smooth strands with a sealed, flat cuticle layer will be naturally more impervious to atmospheric conditions as well.

Common Humectants

  • Glycerin
  • Propylene Glycol
  • Honey
  • Agave nectar
  • Sorbitol
  • Sodium PCA
  • Panthenol
  • Hydrolyzed silk protein
  • Fructose

Once you understand your climate, the weather and what your hair likes and dislikes, it will help lead to better hair days by knowing when to use products with certain humectant or anti-humectant ingredients inside. As the seasons change, so will your hair needs which is why a variety of products based on the weather is good to have. If you buy a new product and you dislike it in the Winter, you may want to shelve it and give it a try in summer where it could become a “Seasonal Holy Grail”.

For more information on Dew Points & Humectants, be sure to check out curly-wavy vlogger Waterlily716‘s video:

This article was originally published in July 2013 and has been updated for clarity and updated information.

Diane Mary

Just a girl passionate about beauty, a big hair product junkie who tries to keep her naturally curly wavy hair as healthy looking and nice as possible.

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