High temperatures and humidity settled in during June over a wide swath of the U.S. A boy fishes from a jetty in Bal Harbour, Fla. The situation is the same for air but involves molecules instead of ...

You have expressed a common misconception. Relative humidity is the amount of water vapor in air divided by the maximum amount the air can contain at a given temperature, expressed as a percent.

Sure, we all complain about the humidity on a sweltering summer day. But it turns out that same humidity could be a source of clean, pollution-free energy, a new study shows. "Air humidity is a vast, ...