It's a T-shirt kind of day in Washington, DC: 85 degrees with 63 percent humidity. We all know those numbers mean hot, but what exactly does that humidity percentage tell us? And why should we care?

The short answer is both terms are different and describe different things about moisture in the air. The dew point is another temperature value. It is the temperature air needs to cool to become ...

MOLINE, Ill. — You hear us talk about it on a fairly regular basis during the summer months. It's not the heat, it's the humidity! So thick, you could slice it with a knife! The air you can wear, ...

Relative humidity measures how much moisture is in the air compared to how much it could hold at a given temperature. It is simply the dew point temperature divided by the air temperature, times 100.