Ozone: Summer days tend to see higher concentrations of this gas, which is harmful when it forms near the ground. Hot and sunny conditions accelerate that process. Ground-level ozone irritates the ...

With the first official 100-degree reading in 13 years on Tuesday, Philadelphia broke a 100-year-old record for a daily high-temperature. And another might fall Wednesday, after what could be a second ...

Earth is hotter than it has been in 125,000 years, scientists say, and Las Vegas continues to break temperature records. The ...

Opinion: Hogan Lovells' Sean Marotta and Danielle Desaulniers Stempel explain how the Supreme Court's new two-step rule to determine the venue for Clean Air Act cases will work.

Humidity in Houston is often discussed due to its impact on how the weather feels, with humidity referring to the water vapor ...

The precautions in Wayne come after more than 160 people were overcome by the heat at graduation ceremonies in Paterson.

Happening now: Unpleasant muggy morning with lots of sunshine. Temperatures may climb even faster than Monday. Afternoon heat ...

After one of the warmest June mornings in records dating to 1872, Philadelphia may experience its first 100-degree reading in ...

Since its launch in the United States, demand for ChillWell 2.0 has surged. Reports indicate a consistent sell-out cycle, ...

For 150 million people across the United States, humidity surged to levels higher than Miami late Monday. Maps show where.

Texas finds itself sandwiched in between weather systems. This pattern will continue to send moisture from the Gulf of Mexico ...

A persistent “heat dome” has settled over the eastern U.S., triggering heat advisories and triple-digit heat index values ...