The temperature on any given summer day may be in the 80s or 90s. So why does it feel so much hotter and oppressive at times? That's the heat index doing its thing. Here's how it works: What is the ...

In the simplest terms, humidity is a natural occurrence of water vapor in the air. It plays a big part in how clouds are made ...

Some hot days feel even worse thanks to high humidity, trapped heat and dew points. Cities are especially vulnerable. By Nazaneen Ghaffar Nazaneen Ghaffar is a reporter on The Times’s weather team. It ...

The first major heat wave of summer has enveloped much of the midwestern and eastern U.S. in a brutal “dome” of record temperatures and high humidity. The dome phenomenon happens when weather ...

An early-season heat dome is building over the Gulf of Mexico and will bring a week of unusual heat and humidity to southern states, from Texas to Florida, and southward into Mexico and the Caribbean.

If you thought the worst of the summer's sweltering temperatures were behind us, think again. Some schools closed early as the late-August heat wave gripping Ohio brought temperatures not seen in ...