The heat index shows how humidity makes hot days feel hotter, and why direct sun can push dangerous conditions even higher.

Add Yahoo as a preferred source to see more of our stories on Google. We may earn revenue from the products available on this page and participate in affiliate programs. Learn More › Electric humidity ...

The humidity may be relative, but the shock is real. Often times in the middle of a D.C. summer you hear people say, "It's not the heat... It's the humidity," and they're right. The humidity makes a ...