More than 150 million Americans are under the highest level extreme heat alerts during a wave of above-average temperatures.

On Monday, dozens of towns across the Mid-Atlantic and the Northeast set or tied records for the hottest recorded temperature ...

More than 150 million Americans are under the highest level extreme heat alerts during a wave of above-average temperatures.

A heat wave is currently affecting about 160 million people, according to the National Weather Service. Here's which states ...

Humidity will soon surge to extreme levels across 40 states. Find out where there will be excessive heat and humidity — and ...

Maps show where extreme humidity and 90- or 100-degree temperatures will affect about 255 million people across the United ...

Heat dome will cause dangerously high temperatures in many places across the country this weekend, especially the Midwest and ...

Extreme heat is impacting states across the country. See maps of high temperature forecasts and heat index levels.

More than 37 million Americans are under heat advisories across the U.S., according to the National Weather Service. Here's ...

An air quality map shows conditions improving in the U.S. on Friday as smoke from the Canadian wildfires subsides.