The relative humidity, in short, measures the amount of water vapor in the air compared to the air temperature. So what’s the problem with that in terms of figuring out how muggy it might be ...

So, what is the difference, if there really is one? To find out, let’s dive into what dewpoint is and what relative humidity is. Dewpoint is a more direct measure of moisture in the air.

For example, the relative humidity on a given day may vary between 90% in the morning and 38% in the afternoon and it still feels relatively comfortable.

Dew point and humidity are related, but different. Here's what dew point actually is and why it is a better indicator of what it feels like outside.

High humidity can often make people feel uncomfortable and have difficulty sleeping. And humid weather is sometimes accompanied by thunderstorms and heavy rain.

Relative humidity, however, is dependent on temperature. Displayed as a percentage, relative humidity tells you how much water vapor there is compared to how much the air could hold at that ...

The dry bulb remains unaffected. The difference between the two readings is then used to calculate relative humidity and other humidity indices.