What is a high humidity number? (link)

Dew occurs when the relative humidity reaches 100 percent. “Dew point temperature is an absolute measure of the amount of water vapor in the air,” Sobel said. If you have a dew point temperature of 65, that means that the outside temperature must decrease to 65 degrees before dew, or water, will form on your lawn.

8 things you didn't know about humidity | PBS NewsHour