In Paterson, New Jersey, more than 100 people needed treatment during two outdoor graduation ceremonies on Monday, as the heat index climbed to 107 degrees. That evening, Mayor André Sayegh declared a state of emergency due to the high heat and canceled all recreational activities.
More than 60 record-high temperatures were set across the country Monday, with more expected this week from the Southeast into New England.
Preliminary daily records were set Tuesday in New York City (which hit 99 degrees), Philadelphia (which reached 100 degrees for the first time since 2012) and Raleigh, North Carolina (which hit 100 degrees).
New all-time June monthly records were set in Boston (101 degrees) and Providence, Rhode Island (100 degrees), and Newark tied its June record of 103 degrees.
Conditions are expected to remain stiflingly hot through the evening hours, according to the National Weather Service.
“Overnight lows are forecast to only drop into the 70s, with urban centers along the East Coast struggling to drop below 80 degrees at night,” the weather service said Tuesday in its short-range forecast.
The sweltering conditions are caused by a high-pressure ridge that is currently parked over the eastern U.S. These systems are known as heat domes because they trap hot air over a region, driving up temperatures for prolonged periods of time.
Some relief is expected later this week, heading into the weekend, but heat and humidity will continue to soar in the coming days.
“The most significant cumulative heat impacts are anticipated across the Mid-Atlantic through Thursday and eastern Ohio Valley into Friday, leading to several consecutive days of oppressive heat,” the weather service said.
Anyone is susceptible to heat-related illness or death, but excessively hot and humid conditions — especially for days on end — are particularly risky for children, people with pre-existing health conditions, older adults and individuals who work outdoors. These health impacts are a significant concern as heat waves become more frequent, intense and longer-lasting due to climate change.
As the eastern half of the country bakes under the heat dome, severe storms could hit parts of Wyoming, Colorado, South Dakota and Nebraska. Heavy rainfall and flooding is also possible for much of New Mexico and far southwestern Texas.
