KEMA Column
Your hair, which you carefully styled this morning, is already frizzy by the time you reach the station. Even though you straightened it with an iron, the waves have returned by noon. These rainy season hair woes are not due to a lack of effort. There is a clear "reason" for the relationship between humidity and hair. In this article, we will unravel the mechanisms behind frizz, volume, and dryness, and introduce ways to manage your hair during the rainy season by learning from the hair care culture in South Korea, a country that shares a similar hot and humid rainy season.
Why does hair become unmanageable in the rainy season? The relationship between humidity and hair
Keratin protein, the main component of hair, naturally tends to absorb moisture. When humidity levels in the air rise, hair absorbs surrounding moisture, causing some of the internal bonds that support its shape to loosen and rearrange. This is the root cause of frizz and excess volume.
What is important here is that hair does not absorb moisture "uniformly." Areas damaged by coloring or heat tools have open cuticles, which allow moisture to penetrate intensively. This creates a discrepancy in moisture absorption between healthy and damaged parts, causing the internal moisture balance of the hair to collapse—this "unevenness" is what triggers the volume and frizz unique to the rainy season. In other words, hair that is easily affected by humidity is hair with weakened internal moisture retention and disrupted surface cuticles. The essence of rainy season hair concerns lies not in the humidity itself, but in the condition of the hair.
South Korea also has a "rainy season"—*Jangma* and the culture of humidity countermeasures
South Korea, a powerhouse of beauty, also has a rainy season equivalent to Japan's. This period, from late June to July, is known as *Jangma*, and the hot, humid, and sultry weather is very similar to the Japanese rainy season. Because of this, dealing with humidity and hair has become deeply rooted as a part of daily wisdom in Korea.
For example, never leave your hair wet. In Korea, the habit of shampooing at night and ensuring your hair is completely dry before going to bed is standard. It is also characteristic that "scalp care" (*dupi-gwanri*), which conditions the scalp as well as the hair itself, is prioritized even more during humid seasons. The concept of addressing issues from the foundation rather than relying on symptomatic treatment during high-humidity periods is a typical approach for a country so advanced in skincare.
The foundation starts with the scalp—prioritize "scalp care" during the rainy season
The scalp also undergoes changes during seasons with high humidity. It is a time when sweat and sebum secretion increase, making it easier to feel stickiness, odors, and itching. When the scalp environment is disrupted, not only does the root lift collapse, making it difficult to style your hair, but it also affects the condition of the hair that will grow in the future.
That said, washing your hair multiple times a day with a strong shampoo is counterproductive. A scalp stripped of necessary moisture will instead attempt to overproduce sebum. The Korean way of thinking is to "cleanse thoroughly, but leave the moisture behind." Reset pore impurities properly with a shampoo of appropriate cleansing power, and after washing, use a tonic to balance the scalp's moisture. It is the concept of applying the same steps used in facial skincare to your scalp.
The key is in "how you dry"—Korean-style drying habits and the concept of moist heat
In fact, the biggest difference in rainy season hair care is in how you dry your hair. Relying on air-drying because of high humidity is a habit to avoid at all costs. Wet hair has its cuticles open and is in its most vulnerable state. If left like that, it will absorb humidity while you sleep or go out, causing frizz and volume.
The Korean drying method starts by gently removing moisture with a towel by sandwiching the hair, then using a hair dryer from the roots. Blow air as if drying the scalp, and save the ends for last. Once the whole head is dry, applying cool air tightens the cuticles, smoothing the surface and reducing the gaps where humidity can enter.
What is important here is not to over-dry. If you apply too much heat and strip away the moisture inside the hair, the hair will become dry and actually become more prone to absorbing moisture from the air. Balancing moisture and heat—the "moist heat" concept that KEMA places at the center of its product development is an extension of this very approach to drying.
"Leave-in" treatments to block humidity—choosing between oils and balms
The role of leave-in treatments is to protect the surface of dried hair. Leave-in treatments for the rainy season have two functions: one is to coat the surface of the hair to prevent atmospheric moisture from entering. The other is to lock in moisture inside the hair, making it less likely for "uneven" moisture absorption to occur.
For hair that is prone to volume or heavily damaged, use an oil type. Applying it mainly to the ends before blow-drying creates a base that protects the hair from heat, and applying a light layer after drying provides a glossy finish that smooths the surface. For those with fine or soft hair who dislike heavy products, use a light-textured balm. Warming it in your palms and applying it to the mid-lengths and ends will suppress volume without stickiness and maintain natural manageability.
From morning style to evening—Korean-style styling maintenance techniques
Finally, there are ways to make your morning styling last longer. The first point is to ensure your hair is completely dry before leaving the house. If you use a flat or curling iron, applying heat while your hair is still damp causes internal moisture to expand rapidly, leading to damage and the return of waves. The golden rule is to style on "dry hair."
Second, the finishing cool blast. After creating the style with warm air, apply cold air to lock the shape in place. Since hair sets its shape at the moment the heat cools, this small step makes a huge difference in staying power. And on days with high humidity, one trick is to tie your hair up rather than forcing it down. It is a standard habit even among Korean men to spend time drying and styling before going out. It is precisely with shorter hair that the precision of drying determines the final look.
And for those who use irons, the rainy season is the time to reconsider the "quality of heat." If you straighten your hair with only dry, high-temperature heat, the internal moisture is stripped away, leading to dryness and actually creating hair that is more susceptible to humidity. With "moist heat" technology that shapes the hair while maintaining the balance of moisture and heat, you can protect moisture while achieving a smooth, straight look that is resistant to humidity. It is one of the most logical approaches to tackling rainy season frizz.
For your daily routine: KEMA's popular items
From foundational scalp care to finishing leave-in treatments for rainy season hair woes, here are our recommended KEMA items.
KEMA Scalp Shampoo
★★★★★
Cleanses away the sebum and stickiness that increase during the rainy season while retaining necessary moisture. The perfect bottle for "scalp care without over-washing."
¥9,020 (tax included)
KEMA Crema Treatment Black
★★★★★
The best hydration in KEMA history. An in-bath care product that saturates the hair with moisture from within to prevent "uneven" humidity absorption and suppress dryness and volume.
¥11,990 (tax included)
KEMA Miracle Bond Balm
★★★★★
A high-repair leave-in balm that reconstructs damaged hair from the inside. Repairs damaged areas prone to humidity absorption, caring for hair volume even into the evening.
¥4,290 (tax included)
Moist Heat Straight Iron DBST-24
★★★★★
A "moist heat" iron that straightens by balancing moisture and heat. It styles while protecting moisture, so your hair stays straight and resistant to humidity. The go-to solution for rainy season frizz.
¥60,500 (tax included)
KEMA Penta S Oil
★★★★★
A "protective base" before heat, and a "finishing touch" after. Coats the surface to block humidity, keeping your hair glossy and smooth all day long.
¥5,940 (tax included)
KEMA: Inheriting the Korean sense of beauty
The rainy season is the time of year when your hair's condition is most honestly revealed. Hair that is disrupted by humidity, conversely, is also hair that tells you where there is "room for improvement." With the Korean aesthetic of order, balance, and harmony at its core, KEMA has pursued hair care that uses advanced liposome technology to deliver beauty ingredients to the deepest parts of the hair, repairing it from within. Rather than fighting against humidity, we focus on balancing the moisture and heat within the hair. This accumulation of care creates hair that remains unshakable even on rainy mornings.
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From scalp care to leave-in treatments, we offer a lineup to support your daily life during the humid season.
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