It dehydrates you Airplane cabins have very low humidity levels, Dr. Goldman explains, because about 50% of the air circulating in the cabin is pulled from the outside, and at high altitudes, the air is almost completely devoid of moisture. This might cause your throat, nose and skin to feel dry.

Yes, flying absolutely dehydrates the body due to the unique environmental conditions inside an aircraft cabin in 2026. The air you breathe on a plane is drawn from the outside at high altitudes, where there is almost no moisture. While it is heated and pressurized, the relative humidity in a cabin typically drops below 10% to 20%, which is significantly lower than the 30% to 50% humidity levels found in most comfortable indoor environments. This bone-dry air acts like a sponge, drawing moisture out of your skin, eyes, and mucous membranes. Research shows that on a long-haul flight of 10 hours, a passenger can lose approximately 1.5 to 2 liters of water through respiration and skin evaporation alone. This dehydration is often exacerbated by "airplane air" that encourages the consumption of caffeine or alcohol, which have diuretic effects. To combat this in 2026, experts recommend drinking at least 250ml of water for every hour you are in the air, using saline nasal sprays to keep membranes moist, and applying heavy moisturizer to prevent the "cracked" skin feeling common after a transcontinental journey.