Historic heat waves leave more than 100 million Americans under heat alerts

More than 100 million Americans are under heat alerts from coast-to-coast on Saturday. Record high temperatures are possible in Redding, California; Reno, Nevada; Denver, Colorado; and Grand Junction, Colorado.

In the West, there is an extreme heat risk in the California Valley with temperatures up to 115 degrees as the long-duration heat wave continues.

In the Midwest, Minneapolis will have a heat index of up to 98 degrees, Omaha up to 112 degrees and Kansas City up to 108.

In the South, the heat index today will reach up to 112 degrees for New Orleans and 109 degrees in Mobile, Alabama.

In the Northeast, the hottest temps of the year so far are expected in the coming days, with heat alerts out from Sunday to Tuesday. New York City could reach a heat index up to 100 degrees, Philly up to 108 and parts of New Jersey up to 111.

The heat will continue in the East for a few days with heat index values in the triple digits through Wednesday. Then a cold front sweeps through and brings a cool down for much of the country Wednesday.

NYC will experience a heat wave with highs in the 90s Sunday through Wednesday, and heat indices around 100.

Record high heat

Las Vegas set a a new all time record high temperature at 120 degrees this week, surpassing the previous record of 117 degrees.

The city also had seven consecutive days of temperatures above 115 degrees -- four of those days were the hottest days on record to hit the city. On Saturday, Las Vegas has a forecast high of 111 degrees finally breaking the streak of temperatures above 115 degrees.

Other cities that had recorded high temperatures on Friday include Denver which hit 201 degrees; Colorado Springs which hit 100 degrees; Salt Lake City, Utah, which hit 105; and Phoenix, Arizona, which hit 116.