If you thought frazzled hair was the summer's biggest beauty bummer, you might want to think again. According to skin experts, the sticky weather can also wreak major havoc on your complexion — we're talking makeup slip-sliding, oil slicks, and even breakouts.

“In simple terms, humidity is the amount of water vapor held in the air," says facialist and Time Bomb skin-care expert Michaella Bolder. "Low humidity comes with colder temperatures and high humidity with warmer temperatures, but our skin likes balance, so either low or high humidity can throw it out of whack."

As Bolder explains, periods of high humidity tend to result in increased sebum production and sweat, which can lead to clogged pores and breakouts. "Plus, the damp, hot weather means our skin is more likely to become host to bacteria," she says. "If you already suffer from acne then you need to take extra care during hot summer months that you're keeping the skin as cool and clean as possible, but the same still applies for those with normal to combination skin types."

So what else can we do about it? Bolder insists that everyone needs to ensure they're cleansing their skin twice a day, every day, and suggests double cleansing in the evening, too. During the day, she advises staying away from any long-wear foundations or non-water-based SPF formulas. "These products won't allow for any perspiration to come to the surface and could potentially block pores and cause congestion," she says.

The theory that you need to lighten up on the hydration front isn't a lie you've been told in order to sell more moisturizer. Bolder puts it this way: "Think of your moisturizer in a similar way to your clothes — lighter in summer, heavier in the winter." She also recommends adding a salicylic acid serum if you have oily or combination skin, to help exfoliate and clear out any dirt and bacteria that cleansing alone can't reach. And for all skin types, Bolder says weekly exfoliation is essential. "It's important to slough off that top layer of dead, dull skin that builds up thanks to the extra sweat, SPF, and pollution," she explains.

Ahead, the best products for humidity-proofing your skin-care routine — so you'll look fresh-faced, even when you feel anything but.