La Niña creating sweltering temperatures across much of U.S., expert says

Several parts of Texas are under excessive heat warnings as temperatures are expected to hit triple digits for the 24th day in a row. Temperatures reached 110 degrees in the Dallas area on Tuesday. The high temperatures caused heat-fueled wildfires to burn several homes near Dallas on Monday and forced several people into mandatory evacuations. 

"We have a pretty significant drought all across north and central Texas. This drought caused us to go into summer much earlier than we normally see," said Sarah Barnes of the Dallas/Fort Worth National Weather Service Forecasting Office.  

Nearly 40 million Americans in parts of California, Arizona and the Central Plains are also facing excessive heat temperatures.