Lots of men say their genitals grow and their erections are better during warmer months, according to a recent article in MEL Magazine.

Amanda MacMillan
July 26, 2018

Sometimes, a story pops up in the news that seems a little silly, but it’s intriguing enough that we just have to do some digging of our own. One of those stories surfaced today, in the form of a trending Daily Mail article all about “summer penis.”

Apparently, guys have been talking about this phenomenon—in which their penises seem to be larger in the summer and smaller in the winter—for years now. Journalist Tracy Moore seems to have coined the term “summer penis” earlier this month in a feature for MEL Magazine (a men's media brand founded by Dollar Shave Club), but she references a Reddit forum from 2016 and a magazine quote from 2009 as the inspirations for her story.

Summer penis is a temporary fluctuation that, “thanks to heat and warmth, gives you a months-long leg-up on shaft size,” Moore writes. “It’d be like if a woman’s boobs suddenly got huge from May to August.” She quotes Reddit users who claim they have bigger penises, better erections, and even larger testicles during the summer.

RELATED: 6 Things Your Partner's Penis Can Tell You About His Health

Moore did plenty of research on the topic, including soliciting anecdotes on social media and speaking with several urologists. Most doctors agreed that several factors could account for a penis’s apparent growth during hotter months: Men may be hydrating more, for example, and blood vessels may expand to regulate heat. (That’s compared to winter months, when blood vessels contract—a known contributor to shrinkage.)

“[W]hen it’s hot outside, you may take in more water, which may in combination with the sweating make it appear like your body or skin is bloated,” Jamin Brahmbhatt, MD, a urologist with Orlando Health, told Moore. “And that may give you the perception that things are larger.”

Urologist Dudley Danoff, MD, author of The Ultimate Guide to Male Sexual Health, told Moore that vasodilation is a likely culprit: Blood vessels dilate, or expand, in warm environments, which causes erectile tissue to enlarge to its maximum volume. (Of course, he adds, maximum volume will still only be reached during an erection—not when a penis is in its flaccid state.)

But the doctors also stressed that these changes are mainly optical illusions, or minor, temporary fluctuations at best. That doesn’t mean that people can’t—and shouldn’t—take advantage of them, or the improved confidence that may come with them. “There’s a reason why people don’t take honeymoons to the North Pole,” Dr. Danoff told Moore. “They go to Hawaii. There’s a reason why a hot tub is attractive for romance.”

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While that all makes a lot of sense, we wanted to get another medical opinion. So we turned to urologist Jesse Mills, MD, director of the Men's Clinic at UCLA, for his take on all things summer-penis-related. Overall, he agrees that hotter is better, in terms of size—or at least appearance of size. 

"Penile size in the flaccid state is purely a function of how much blood flow is circulating in the penis," Dr. Mills said in an email. "The warmer the environment, the more show a man is going to have."

But Dr. Mills also points out that not all summer activities are going to help a man show off his assets. "Stick a guy in an ice cold lake in the middle of summer and his penis will shrink to winter size."