Short answer: Yes, your beard does grow faster in the summer. Why?
Androgens, specifically testosterone, play a major role in how fast your beard grows. More testosterone, better growth. Several factors determine your testosterone level/production- from your diet, exercise level, sex life, and even genetics. But researchers from the Centre of Skin Sciences at the University of Bradford in the United Kingdom also found that a certain time of year correlates to faster beard growth rates.
Their research shows that beard growth rate is actually slowest during the winter, a time when a lot of guys are trying to grow their beards. Beard growth rates dramatically increase during the summer months, peaking in July. These growth rates correspond to testosterone levels, which are lowest during the winter and at peak during the summer.
So if you want an epic winter beard, start growing in the summer to capitalize on that accelerated beard growth. Don’t fall victim to the misconception that a summer beard will make you noticeably warmer.
Remember, summer beard care differs slightly from your winter routine. I recommend you wash your beard more often during the summer months than in the winter. Heat, humidity and sweat damage your whiskers, and sweat and its residual salt turn your gloriously luscious beard into a dry, crispy mess. With this additional washing comes the need to moisturizer more often.