More than 85 million Americans live in areas under excessive heat warnings according to the National Weather Service.
There is a heat advisory in effect for the New York metropolitan area as temperatures are expected to reach near-record levels on Sunday, with a high of 92 degrees and a heat index of 104 degrees in New York City.
In Texas, the regions around Houston, Austin and San Antonio are likely to record temperatures over 100 degrees on Sunday, while one area near the state's border with Mexico could get as hot as 106 degrees.
According to the NWS, Boston is expected to hit 99 degrees on Sunday, breaking the 1933 record for the highest temperature in a single day.
Baltimore and Washington, D.C. are both under heat advisories, with highs in the 90's and heat index in the 90's.
A heat advisory is in place in Memphis, Tennessee, with a projected high of 97 degrees on Sunday, though the NWS noted that projected rain showers could bring temperatures down in the northern part of the city.
According to the NWS, the temperature in St. Louis could reach a high of 102 degrees on Sunday, but that will be the last hot day of the year.
According to the NWS, the Pacific Northwest could get hot this week. The agency has issued excessive heat watches for the area around Portland, Oregon, and in Seattle, where temperatures could reach highs in the 90s this week. Air conditioning is not usually used in the Pacific Northwest.
Climate change contributes to the heat wave gripping much of the country, according to experts. The president said last week that he would take executive action on climate change. The Senate was unable to reach a deal on climate and energy legislation after Sen. Joe Manchin said he wouldn't support any legislation that included spending or tax increases.
Europe and Asia have been hit by a heat wave this summer. The United Kingdom and Taiwan both set new all-time high temperatures over the past month.
The major temperature records were shattered in the heat waves.
Biden says he will take executive action on climate after the legislation is passed.