PORTSMOUTH, Va. (WAVY) — Humidity on a hot summer afternoon — it’s the “air you can wear,” many say — the air that feels so thick and heavy it’s like we’re nearly swimming instead of walking.

The dew point is the decider to us humans, it’s the value that truly depicts how the air feels. The higher the dew point, the higher the humidity. The lower the dew point, the lower the humidity.

Essentially, it’s the air’s saturation point. When dew points reach the 60s and 70s and get close to the air temperature, the air gets easily reaches saturation. The air fills with water as millions and millions of water vapor molecules attach themselves to the air particles. So to us humans, it feels muggy, thick and heavy. Why?

Because our perspiration can’t evaporate.

In the hot summer sun, our bodies begin to perspire and release heat. To cool off, we need that heat to escape off our skin. However, during those muggy and humid days, that heat being released from our bodies can’t escape, and our sweat can’t evaporate, because the air is already full of so much water.

It’s the equivalent of trying to dry yourself off with a wet towel.

So yeah, most of the time in our neck of the woods, it’s not the heat, it’s the humidity.