(CNN)Over a dozen cities in the central and eastern United States could break record high temperatures on Sunday, and a few of them may do the same thing on Monday.
In the last week, the US saw more than 450 daily high temperature records fall, according to the National Oceanic and Atmospheric Administration. Sunday's high heat is likely add a few more locations to that list.
Besides the daily high record tallies, over 75 monthly heat records were set as well. And nearly a dozen locations this week set all-time high temperature records, including Turkey, Texas, (117°F) and Hialeah, Florida (100°F).
For many cities in the central and eastern US, summer heat waves can feel downright brutal due to high humidity. That will be the case Sunday for Cincinnati, St. Louis, Memphis, Nashville, Baltimore, and Raleigh, North Carolina, which will have heat indices (what temperatures feel like) above 100°F.
Even cities farther north like Boston, Philadelphia and Burlington, Vermont, will see high temperatures Sunday topping 95°F.
"Nearly 90 percent of the contiguous US is expecting afternoon high temperatures of 90°F or higher over the next week," said CNN Meteorologist Haley Brink. "However, the overnights are expected to remain very warm as well. Some cities will see the overnight lows fall only to near 80°F."
"This makes longer summer heat waves even more dangerous to those without access to air conditioning to cool their body down," Brink said.
In the past week, nearly 50 records were set for hottest overnight low temperatures, including Lubbock, Texas, which only dropped to 86°F on July 14.
Temperatures need to drop to at least 80 degrees for your body to recover from the intense day heat. People can lose up to 2 liters of fluid overnight through sweating if temperatures don't dip below 85°F.
In 2019, 63 people across the US died from heat related illnesses, the third highest weather-related fatalities after rip current and flooding deaths, according to the National Weather Service. In the last 30 years, extreme heat has been the leading cause of weather-related fatalities in the US.
Boston and New York are under a heat advisories Sunday. Knoxville, TN and Erie, PA are not under advisories despite higher heat indices. They will not meet the criteria set by the National Weather Service because each area of the country has its own guidelines.
In the Midwest, cities like Minneapolis, Chicago and Milwaukee -- all under heat alerts on Saturday -- will finally see some relief thanks to a cold front. The Chicago area will go from mid 90s Saturday down to a high of only 80°F on Tuesday. Detroit and Cleveland will see a similar cool down after the front moves through Sunday.