The kindest way to dry curly hair is to remove excess water by blotting or gently squeezing with a soft towel, then let it dry with little or no heat, and never rub or comb it when it is wet and unprotected. If you do use a dryer, keep it on a low heat, at a distance, and moving. Drying matters because wet hair is at its weakest and heat is the most reliable way to wear hair down.
What happens to hair when it is wet
Hair swells when wet because water temporarily breaks hydrogen bonds in the strand, according to cosmetic scientist Michelle Wong. Wet hair is weaker and stretchier, which makes it more vulnerable to rubbing and pulling, even though water itself is not very damaging and the evidence for the popular idea of "hygral fatigue" is weak. This is the reason for gentle towel use, for avoiding rough handling after a wash, and for not sleeping on wet hair.
A second reason is the scalp. Wong notes that a scalp left damp for long periods may favour Malassezia, the yeast linked to dandruff, so faster drying can help scalps prone to flaking. The NHS describes dandruff as common and harmless, and treatable with anti-dandruff shampoo, so this is a consideration rather than a reason for alarm.
Towels
Rubbing hair with a rough towel is hard on the cuticle and tangles curls. Instead, tip your head forward and squeeze sections upward towards the scalp, or press the towel against the hair and release. A microfibre towel or soft cotton t-shirt is gentler than a thick terry towel. Wong suggests microfibre may dry faster with less damage, but her explanation is her own reasoning, not a tested result, so choose whichever your hair tolerates. Apply leave-in and styler before towel drying if you want to keep clumps defined.
Heat: what the research says
The clearest data on dryer distance is an older study by Crawford and colleagues, summarised by Lab Muffin, in which hair samples were washed and dried every day for 30 days.
| Drying method | Hair temperature | Approximate drying time |
|---|---|---|
| Air drying at room temperature | About 20 degrees Celsius | About 2 hours |
| Dryer held 15 cm away | About 47 degrees Celsius | About 60 seconds |
| Dryer held 10 cm away | About 61 degrees Celsius | About 30 seconds |
| Dryer held 5 cm away | About 95 degrees Celsius | About 15 seconds |
All of the blow-dried samples showed cuticle lifting and cracking, which worsened as the dryer got closer and hotter, and the closest distance produced bubble hair, where water boils inside the strand. Wong reports that heat damage rises with temperature, with severe damage from around 180 degrees Celsius, and that heating wet hair above about 90 degrees Celsius risks bubble hair.
Not always. A 2011 study reported more damage in air-dried hair than blow-dried hair, though Wong disputes the result and notes it has not been replicated. Air drying keeps hair wet and fragile for longer, which matters if you go outside or sleep before it is dry. The safest compromise is to air dry as far as practical and use low heat at a distance to finish.
Diffusers and dryers on curls
- Use the lowest heat setting that works, and a diffuser attachment to spread the airflow so curls do not blow around and tangle.
- Keep the dryer moving and at a distance. Keeping it away from the strands follows the same logic as the distance data above.
- Do not heat-dry soaking wet hair. Remove water with a towel first, then dry in sections.
- Use a heat protectant on wet hair before drying, as the American Academy of Dermatology advises before any heat styling. Use the lowest temperature that gives the style you want.
- Stop short of bone dry if you can. Leave a little dampness to finish off in the air.
Once the style is set and fully dry, you can loosen any gel cast gently with your hands. Avoid touching curls while they are drying, as this tends to cause frizz.
Fitting drying into the wider routine
Drying is the last step of wash day, and the same logic applies at night: go to bed with dry or nearly dry hair, then use a bonnet or silk pillowcase if you find it helps. If you notice more breakage after using a dryer, look at heat, distance and how much conditioner and protectant you are using, and see detangling without breakage for gentle handling once the hair is dry.
Drying time, density and scheduling
Thick, dense or long hair takes much longer to dry than fine or short hair, so it is worth planning wash day around the drying stage, not squeezing it in before leaving the house. Starting in the morning and finishing with a short low-heat session at a distance is usually kinder than rushing everything with a hot dryer. If you will be outdoors in cold weather, make sure the hair is dry first, as damp hair loses comfort quickly even if it is not damaged by the cold.
If you are travelling or short of time, a pragmatic option is to squeeze out as much water as you can, apply your styler, and finish with a few minutes of low, distant heat on the roots only. The roots dry slowest and sit closest to the scalp, while the more fragile ends are best left alone to dry in the air.
Frequently asked questions
Is air drying better than blow drying?
Not necessarily. Heat damage is real, but air drying keeps hair wet and weak for longer, so low heat at a distance is a reasonable compromise.
Which towel is best for curly hair?
A soft microfibre towel or cotton t-shirt, used to squeeze or blot. Avoid rubbing with a rough towel.
How far should a hairdryer be from my hair?
In the Crawford study, hair temperature rose from about 47 to 95 degrees Celsius as the dryer moved from 15 cm to 5 cm. Keep it moving and further away.
Can I sleep with damp hair?
It is best not to. Wet hair is weaker and more easily damaged by friction, so dry it as far as you can first.