The most important thing about grooming your beard for summer
Though many believe they have insulating properties, they actually don't really do much to keep your face warm, according to GQ. In fact, a beard can actually have a chilling effect, as the hairs keep sweat close to your face, providing a pleasant feeling in the breeze.
That makes them perfectly acceptable to wear in the summer, as fashion dictates (though maybe not for much longer) - provided they are well taken care of.
You may think that as long as you're taking care of your beard and trimming it properly in length, as well as keeping it off your neck, you're good to go. But you're not quite all the way there in the warmer months, which raises the importance of another step.
Though you should be cleansing and exfoliating the skin under your beard throughout the year, the heat and humidity of summer necessitates this even further. Heat and humidity can mix unpleasantly with any sweat, dirt, or dead skin cells, which can irritate the skin underneath or even cause breakouts. Additionally, it can make your beard appear dirty or take on an odd smell.
But that is easily remedied. Specialized formulas called "beard wash" exist, and they're sold pretty much everywhere these days. They claim to be specially formulated to get underneath the beard and clean the skin.
But these beard washes are pretty expensive and there's no reason to go that specialized - your beard isn't that special. Any "all over" (face, hair, skin) wash would also work perfectly, as well as shampoo if your beard is on the shallow side.
Remember, however, that just like you should only wash your face about twice a day, the same goes for the skin under your beard.