Dangerous Heat Dome Raises Risk of 1,000+ Heat-Related Deaths This Holiday Week (Video)

A growing heat dome is putting more than 250 million Americans at risk of a potentially deadly heat wave — just as the country prepares to celebrate its 250th birthday.

“Heat waves on average kill more Americans than any other type of severe weather including tornadoes, hurricanes, floods, and lightning, and yet heat waves often do not get sufficient attention. It is AccuWeather’s observation that the number of people sickened and tragically killed by heat waves tends to be significantly underestimated due to the fact that extreme heat can exacerbate other pre-existing medical conditions. Many deaths during heat waves are attributed to other causes, such as heart attacks, strokes, and even some drownings, but the actual underlying cause was the extreme heat,” said AccuWeather Chief Meteorologist Jonathan Porter.

The AccuWeather Forecast for the Heat Dome

• The “Fourth of July Week Furnace” is a dangerous heat dome that will bring temperatures 10-20 degrees above the historic average, including some record high temperatures across the Central and Eastern United States this week
• AccuWeather RealFeel® Temperatures will surge above 110 degrees across 16 states, including New York, Illinois and Virginia
• There will be daily record highs along with record warm nights, which can increase the risks of prolonged heat exposure
• The AccuWeather HeatWave Severity Index™ is forecasting a strong or severe heat wave and span across wide-ranging areas including: Raleigh, NC, Philadelphia, Chicago, Washington D.C. and New York

AccuWeather Founder and Executive Chair Dr. Joel Myers emphasizes risks of exposure to prolonged extreme heat can be deadly, especially for people who don’t have access to air conditioning and other ways to cool down, especially at night.

“This has the potential to be lethal to over a thousand people when you take into consideration all the impacts across the country from this heat wave. Many of the deaths will not be reported as heat-related deaths,” said Dr. Myers. “The real danger we are concerned about is what occurs when you string together several days in a row of extreme heat. The more days the heat wave goes on, between the high temperatures and extremely warm nights, the more harmful it is to the body. It puts more stress on the body.”

Looking Back at a Past Deadly Heat Wave in the United States

In 2023, public health official approximate that 900 people were killed in the Southwest United States when the region experienced 110-degree heat for 31-straight days.

“The current heat wave will not be as long, but it will be more deadly for two reasons. One, that was dry heat in the Southwest. This heat in the Northeast is accompanied by much higher humidity, and the nights are much warmer. The humidity was much lower in the Southwest with more wind there. Plus, more people live in the Northeast,” Dr. Myers added.

“We cannot emphasize enough how dangerous heat waves can be for so many. They pose the greatest risk to older adults, infants and young children, and people with chronic medical conditions, as well as those who are pregnant, people who work outdoors, and people without access to air conditioning. We are especially urging people to check on family members, neighbors, and friends who may be most vulnerable. A simple phone call or visit can make a life-saving difference during periods of dangerous heat,” added Porter.

Impacts of the Heat Dome During Outdoor Holiday Week

This week’s risk is particularly high given the Fourth of July Holiday will draw millions outdoors in the extreme heat to celebrate America250.

“Where there are large gatherings, it is conceivable that emergency services that are not prepared could be overwhelmed. It is important that first responders and hospitals are properly staffed and prepared for this extreme heat event.” Dr. Myers said.

AccuWeather Heatwave Counter and Severity Index™
The exclusive AccuWeather HeatWave Counter and Severity Index™ has been developed by AccuWeather to properly measure and compare heat waves. It considers the magnitude, duration, and intensity of each heat wave so they can be compared. For this purpose, AccuWeather defines heat waves as consisting of at least three or more consecutive days in which the high temperature exceeds a location-specific threshold. For example, in New York City, Chicago and Philadelphia, this threshold is set at 90 degrees Fahrenheit. In Raleigh, this threshold is set at 95 degrees Fahrenheit. The severity depends on the duration of the heat wave and the extent to which temperatures exceed the threshold.

AccuWeather RealFeel®
AccuWeather RealFeel® Temperature, which was patented, combines 14 factors to provide the most accurate measure of how representative the current or forecast weather conditions really “feel” to an appropriately dressed person. Find your current and forecasted AccuWeather RealFeel® for the sun and the shade on the AccuWeather app.