Why Does Humid Weather Make Hair Frizzy?

iStock
iStock

People with long hair know that even the most meticulously primped 'do is at the mercy of the weather. When the air is humid, hair can start to crimp, curl, or frizz the moment you step outside. Don't just curse the weather every time your hair takes on a mind of its own: the chemical makeup of your locks is also to blame.

A strand of hair is composed of bundles of a fibrous protein called keratin, and the shape and structure of your hair is determined by how these proteins bind together. Keratin molecules contain high amounts of the amino acid cysteine, which in turn contains sulfur atoms. When two keratin chains are nearby, the sulfur atoms from the neighboring molecules can react to form a strong disulfide bond. These bonds lock keratin molecules together and maintain their composition whether your hair is wet or dry. You have them to thank for much of your hair's durability and strength.

Hydrogen bonds are much more numerous in hair, and a lot more fickle. They form when a positively charged hydrogen molecule gets caught between two electronegative atoms in a strand of hair. Unlike disulfide bonds, the hydrogen bonds that form between these atoms are easily dissolved when wet. They break down and form anew each time you take a shower and dry your hair. They're also affected by the humidity in the air.

Instead of breaking down the hydrogen bonds in hair, the right level of humidity produces these bonds in greater numbers. More hydrogen molecules provide more opportunities for hydrogen bonds to form with keratin proteins. As more bonds form, proteins start to double back on themselves, resulting in curly or frizzy hair.

These effects are amplified in hair that's especially dry. Dry hair tends to soak up moisture in the air like a sponge, breaking the strand's outer shaft and making hair look frizzy. This is why hair that's been damaged by heat, chemical coloring, or an overuse of products is often more vulnerable to humid weather.

One way to fight the frizz is by moisturizing your hair before leaving the house. Conditioners, natural serums, and all-around gentler treatment can help cut down on dryness. If that doesn't work, we suggest avoiding tropical climates whenever you can.

Wayfair’s Fourth of July Clearance Sale Takes Up to 60 Percent Off Grills and Outdoor Furniture

Wayfair/Weber
Wayfair/Weber

This Fourth of July, Wayfair is making sure you can turn your backyard into an oasis while keeping your bank account intact with a clearance sale that features savings of up to 60 percent on essentials like chairs, hammocks, games, and grills. Take a look at some of the highlights below.

Outdoor Furniture

Brisbane bench from Wayfair
Brisbane/Wayfair

- Jericho 9-Foot Market Umbrella $92 (Save 15 percent)
- Woodstock Patio Chairs (Set of Two) $310 (Save 54 percent)
- Brisbane Wooden Storage Bench $243 (Save 62 percent)
- Kordell Nine-Piece Rattan Sectional Seating Group with Cushions $1800 (Save 27 percent)
- Nelsonville 12-Piece Multiple Chairs Seating Group $1860 (Save 56 percent)
- Collingswood Three-Piece Seating Group with Cushions $410 (Save 33 percent)

Grills and Accessories

Dyna-Glo electric smoker.
Dyna-Glo/Wayfair

- Spirit® II E-310 Gas Grill $479 (Save 17 percent)
- Portable Three-Burner Propane Gas Grill $104 (Save 20 percent)
- Digital Bluetooth Electric Smoker $224 (Save 25 percent)
- Cuisinart Grilling Tool Set $38 (Save 5 percent)

Outdoor games

American flag cornhole game.
GoSports

- American Flag Cornhole Board $57 (Save 19 percent)
- Giant Four in a Row Game $30 (Save 6 percent)
- Giant Jenga Game $119 (Save 30 percent)

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Expeditions Gather Climate Change Clues on Mount Everest in Two New Documentaries

Team members climb up a slope during the expedition to find Sandy Irvine's remains on Mount Everest.
Team members climb up a slope during the expedition to find Sandy Irvine's remains on Mount Everest.
Matt Irving/National Geographic

Two one-hour documentaries premiering tonight reveal what Mount Everest is really like—and what scientists can learn from studying it.

Both docs are produced by and airing on National Geographic. In Lost on Everest, premiering at 9 p.m. EDT, climber Mark Synnott and Nat Geo photographer Renan Ozturk lead a team of seasoned mountaineers on a mission to discover what happened to Andrew “Sandy” Irvine, who vanished with fellow explorer George Mallory during the first Everest climb in June 1924. While Mallory’s body was located by a BBC-sponsored operation in 1999, Irvine’s exact fate has remained a mystery for nearly a century since his disappearance. As Synnott and his companions search for evidence, they encounter their own harrowing set of obstacles, from hurricane-force winds to medical emergencies.

Climbers on Mount Everest
Climbers ascend the Khumbu Icefall, a notoriously dangerous section of the summit route.
Mark Fisher/National Geographic Society

But Mount Everest isn’t only a challenge for adventure-seekers and intrepid investigators—it also holds thousands of years’ worth of information about how climate change has altered the environment, which can help scientists predict its future effects. In Expedition Everest, airing at 10 p.m. EDT, actor Tate Donovan narrates the journey of an international group of scientists and climbers with an ambitious set of data-collecting objectives.

One task is to use drones, laser scanners, and cameras to capture footage of every inch of the ascent, so researchers can create a 360-degree portrait of the mountain and track how glacial melt alters the landscape in the coming years. Since the Himalayas contain the water supply for roughly one-fourth of the world’s population, the increase in glacial melt—which has already doubled since 2000—could threaten the futures of billions of people living in the region.

Scientists drill ice cores on Mount Everest
Mariusz Potocki and members of the National Geographic and Rolex Perpetual Planet Everest Expedition team collect the highest-ever ice core at 8020 meters (26,312 feet) near the South Col of Everest.
Dirk Collins/National Geographic Society

Even more immediate is the risk of flash floods, which are difficult to predict without a constant feed of weather data from high altitudes. Another goal of the expedition is to install weather stations at five locations along the climbing route, which will monitor temperature, humidity, air pressure, wind speed, and other factors that help alert meteorologists to an impending flood.

Some researchers have joined the expedition to drill deep into the ice at an altitude above 8000 meters (26,000 feet)—Mount Everest's "death zone"—and collect ice cores. These long tubes of ice reveal how the atmosphere has changed over thousands of years. Others are collecting similar cores of sediment at the bottom of a lake, as well as examining how plant and animal life has adapted to the warming temperatures and rising water levels.

Overall, Expedition Everest illustrates how the Himalayas function as an early indicator of what climate change will do to other places.

As climate scientist Anton Seimon explains in the documentary, “We’re getting a window into what the rest of the world is starting to experience—and likely to experience in growing proportions.”

You can watch the double feature tonight, June 30, at 9 p.m. EDT on National Geographic.