Mythbusters: Does Hair Grow Faster In The Summer?

How’s your hair during the summer months? 

Maybe you’re getting ready to get a new haircut to escape the heat. Maybe you’re excited to get beach waves for your vacation. Or maybe, if you’ve heard the rumors, you’re looking forward to finally growing out your hair. Because hair grows faster in the summer, right?

Or does it really? In today’s ZALA Mythbusters, we’ll answer the question: does hair grow faster in the summer?

Hair growth facts

Although hair grows at a different pace per person, the average growth is about half an inch a month or six inches per year. For some people, this number could be smaller. For others, it could be much more.

For over a thousand years, people have continuously experimented with their hair. This has resulted in dozens, if not hundreds, or myths, rumors, and beliefs. And one belief about hair growth is that hair grows fastest during the summer months.

Hair growth factors

Before we explore that myth, what are the different factors that affect our hair growth, anyway? Actually, there are many things that could affect how fast your hair grows, but here are some of the most common factors:

• Age. Young people, especially teenagers, have the fastest rate of hair growth. As we grow older, our hair growth also tends to slow down due to age. This is the main reason why 
• Sex. Males tend to grow hair faster than their female counterparts. Turns out it wasn’t just an illusion–men really do grow hair longer, faster.
• Race. Researchers have found that African men grow hair slowest while Asian men grow hair fastest. This is due to the subtle differences in genetic makeup.

But is it true that the hot weather can really make hair grow faster? Many people will say that their hair seemed to have grown much faster over the summer, but there’s no proof that it’s a scientific fact and not just an observation bias. 

Seasonal changes in hair growth

In one study, researchers from the University of Bradford observed the hair growth of 14 Caucasian men. It was found that their hair grew faster in March. Hair growth then subsequently grew slower as September arrived, reaching peak hair loss in mid-September.

The difference in hair growth lies in the amount of time it takes each individual strand to reach the different hair growth phases. 

There are three phases of hair growth: 1) the anagen or the growth phase 2) the catagen or the slowing of growth 3) the telogen or the falling out phase. Each strand undergoes each phase at a different time, and how long your strand lasts in the specific stages also differs from person to person. 

During the study, the reason why hair seemed to grow faster in March was that 90% of the hair strands were in the anagen phase, which meant 9 out of 10 strands were still growing.

Does hair grow faster in the summer?

The result of the study suggests that warm weather does have an effect on how fast hair grows.

However, don’t disregard your hair care routine during this time! Summer months can be very drying on your hair, and the extra humidity could make your hair frizzy too. It’s very important to stay on top of your regimen during the summer months, especially when it comes to using hair sunscreen.

For more ZALA Mythbusters, don’t forget to check out our ZALA blog!