Just when you thought you’d solved your transitional winter-to-spring hair woes, here comes chlorine, sunshine, salt water and humidity. If your usual routine is to throw your hands in the air and deal with it all in September, have a look at these new products and D.I.Y. routines.

Lighten Up, Gently

Remember Sun In? The drugstore spray-on hair lightener that was all the rage in the 1980s is getting a luxury makeover courtesy of companies like IGK (Summertime hair lightening spray, $27) and Ouai (Sun of Beach Ombré spray, $24).

“The Sun In concept was cool, but it was done wrong,” said Aaron Grenia, a founder of IGK. “It was basically hydrogen peroxide, and it really lifted and had a lot of power. With ours, we’re using a gentler, more hydrating formula — it’s lemon and chamomile, coconut oil and coconut water.” The results are noticeable but subtler, Mr. Grenia cautioned. “It’s also better for those with lighter hair to begin with,” he said.

Alternatively, the colorist Rita Hazan suggests this at-home hack: “Brew chamomile tea and put it in a spray bottle to spritz your hair while you’re in the sun to lighten it a bit. There are flavonoids in the tea that help to gradually lighten hair over time, even darker tones.”

Clean Out Your Cleansers

With humidity and city grime, chances are you suds up your strands more often in summer. But Whitney Bowe, a dermatologist in New York, suggests rethinking the way we wash our hair.

“People love to lather,” Dr. Bowe said. “We’re obsessed with this squeaky-clean feeling and then putting on conditioner with silicones that act as a Band-Aid for your hair. Instead we should be cutting out harsh detergents. We should be preventing damage from happening in the first place.”

She’s hardly alone in her philosophy. A slew of new hair cleansers dispense with the usual formulas. Hairstory, with its New Wash, an aloe- and oil-based hair cleanser, is especially passionate about its methods ($40). The single product, with recently released variations for a deeper cleanse (New Wash Deep) or more hydration (New Wash Rich), is intended to replace both your shampoo and conditioner and to address all hair textures.

The suds-less wash does take some work (you have to truly work in the product and rinse repeatedly or risk oily strands), but it can produce nice, hair-softening results.

A breezier alternative is something in between, like the Glacial White Caviar Resort Cleansing Balm from the Barcelona company Miriam Quevedo ($60). Sulfate-free, with sweet almond oil as its second ingredient, the concentrated formula smells lovely and can help temper frizz.

Keep Your Scalp Happy

Once upon a time, you slathered conditioner all over your hair and scalp and called it a job well done. But if you heed the Briogeo founder Nancy Twine, you’d give your scalp the separate treatment it deserves.

“Summer is a very sweaty season,” Ms. Twine said. “What happens is sweat combines with your normal hair product, and you really start to build up on the scalp.” Briogeo Scalp Revival charcoal and peppermint oil cooling jelly conditioner ($36) “is a really good way to detox and has absorbent qualities,” she said. “At the same time, the conditioner is very lightweight so your roots aren’t weighed down.”

Ms. Twine said the jelly is suitable for all hair types, including black hair like her own, and that she created it specifically for her needs. “I’ve always had issues with a dry scalp,” she said.

The drugstore line Yes To offers a charcoal conditioner for $7.99 with lightweight conditioning results although it lacked the soothing aspect of the Briogeo option.

If you have colored hair, the hairstylist Eliut Rivera, an Upper East Side favorite, suggests two in-salon treatments ($45 per treatment). “I use the Olaplex 2 treatment on my clients, put their hair under a plastic cap and then put them under heat,” he said. “I would do that right at the beginning of summer and then again right after.”

Seal in Your Wet Hair

Speaking of colored hair, chlorine can be quite the land mine. Blondes and those with highlights will want to coat their hair before taking a dip. “Water itself is actually super damaging to hair,” Dr. Bowe said. “When your hair gets wet, the hair fibers themselves will swell. That will make your hair very weak and vulnerable to damage.”

An at-home solution is to slather your hair in something that coats, like coconut oil, before going for a swim. IGK recently released Blocked Water-Resistant Hair Shield ($29), a creamy wax designed to prevent water from entering the cuticle. “It’s like swim cap for the hair without actually wearing one,” Mr. Grenia of IGK said.

It can also double as a styling product. “In the salon, one of our stylists discovered that it’s great as a blow-dry aid, especially for baby hairs on the hair line,” he said.

Hair already tinted swimming pool green? In late June, David Mallett, whose Paris salon draws clients like Charlotte Gainsbourg and Karl Lagerfeld, is releasing the handy Blush Hydration Spray ($45). With raspberry vinegar and organic tomato extract, the formula was created to cancel out Hulk-ish tones.

Then there are the roots. Clémence von Mueffling, the founder of the Beauty and Well-Being site — her new book, “Ageless Beauty: The French Way,” was released this week — says her summer must-have is the Color WOW hair compact ($34.50), to disguise gray hair. “It will hold you over until you have time to visit your colorist,” she said.

Take It Chill

But the truth is, summer is meant for freewheeling, ditching obligations (ideally!) and kicking back. If the idea of overhauling your hair-care regimen sounds onerous, Ms. von Mueffling has this simple tip: Be gentler when drying your hair.

“If my hair is wet all the time from the ocean or pool, I’ll be sure I gently squeeze water out and let it dry naturally,” she said. (Dr. Bowe agrees and loves the quick drying Aquis hair towel, $30.)

Mr. Rivera says that perhaps the most important part of summer hair care is “putting down your hot tools.”

“If you don’t want to feel like you need a million products, just doing that will make a big difference. It’s summer, after all. Embrace the season.”