*Millions of Americans are facing dangerous heat and humidity going into the July Fourth holiday as a major heat wave spreads ...

Thursday was the peak of this brutal heat wave, with heat index values topping 110 degrees in several Connecticut towns.

It’s during times like this that you often hear people talk about the “heat index” and “how hot does it feel?” That’s because temperature and heat index are two separate things.

Temperatures are skyrocketing for the third straight day across the Eastern US, but there’s at least three different ways to ...

The metric of how hot the air actually feels has roots in a 1979 journal paper called “The Assessment of Sultriness.” By Andy Newman In recent days, you may have seen or heard many mentions of a ...

Temperatures in the triple digits are expected through the Fourth of July weekend and beyond. Follow these expert-approved tips to learn how to read your local heat index to determine if it's safe to ...

Michigan's heat wave this week will feel even warmer because of high humidity. Here's how the heat index works.

If the dew point is 32 then the relative humidity is 100%, and we all know you don’t walk outside and start sweating at that ...

That is because the dew point is a measure of how much water vapor is in the air and relative humidity is a measure of how much water vapor is in the air relative to how much water vapor could be in ...

The number on the thermometer only tells half the story. Here’s what to know about heat index—and why some scientists are rethinking how it is calculated.