Blistering heat dome to scorch cities coast to coast for 2nd week

Sixty-five million Americans from coast to coast are under heat alerts as the life-threatening heat dome continues for the second week.

The Northeast, Southeast and West all saw daily record temperatures shattered this weekend, including 98 degrees in Philadelphia; 100 degrees in Greenville, Mississippi; and 108 degrees in Merced, California.

This weekend, Washington, D.C., and Baltimore hit 100 degrees for the first time in June in 12 years.

On Monday, the dangerous heat is impacting the Southeast, the Deep South and the West.

Temperatures are forecast to soar to 96 degrees in Atlanta; 94 degrees in New Orleans and Nashville, Tennessee; 100 degrees in Little Rock, Arkansas; 99 degrees in Oklahoma City; 98 in Dallas; 109 in Phoenix; 97 in Salt Lake City; and a blistering 110 in Las Vegas and Palm Springs, California.

Areas in South Dakota, Iowa and Minnesota that faced catastrophic flooding in recent days will also be dealing with the scorching heat on Monday.

This week, temperatures will remain extremely hot in the South, from Texas to Kansas to Arkansas to Florida.

The greatest heat risk will be in Oklahoma. Oklahoma City is under extreme heat risk -- the highest level -- due to the combination of hot afternoons and very warm nights.

There are hundreds of deaths each year in the U.S. due to excessive heat, according to CDC WONDER, an online database, and scientists caution that the actual number of heat-related deaths is likely higher.

Click here for tips on how to stay safe in the heat.