An intense and nearly historic heat dome is baking much of the United States this week, bringing dangerous temperatures to regions unaccustomed to such extreme heat this early in the summer. Cities like Boston, New York, and Philadelphia are experiencing sweltering conditions that haven’t been seen in over a decade.
The heat wave is particularly threatening because it’s hitting before many residents have had a chance to acclimate to the rising temperatures. Meteorologists warn that the combination of high heat and humidity is creating hazardous conditions for millions of people.
The dome of high pressure settled over the eastern U.S. is trapping hot air from the Southwest. This weather pattern broke a key measurement of high-pressure strength on Monday, marking it as the third-highest reading ever recorded for any date, leading to what experts are calling a ‘near historic’ heat wave.
Forecasters predict that the worst of the heat will peak for Northeastern cities on Tuesday. Nearly three-quarters of the U.S. population—about 245 million people—will endure temperatures of 32 degrees Celsius or higher. Additionally, 33 million people are expected to face blistering temperatures of 38 degrees Celsius.
The government’s heat health advisories highlight the highest level of heat risk in areas stretching from Chicago to Pittsburgh and from North Carolina to New York. These soaring temperatures, coupled with high humidity, are unusual for many places in the region.
New York hasn’t recorded temperatures of 38 degrees Celsius since 2011, and Philadelphia, which is forecasted to have consecutive days of extreme heat, hasn’t hit that mark since 2012. In downtown Baltimore, temperatures climbed into the upper 30s Celsius by early Monday afternoon, prompting many residents to seek relief at cooling centers and resource hubs.
As the heat wave continues, officials urge residents to stay hydrated, avoid prolonged exposure to the sun, and check on vulnerable neighbors, including the elderly and those without access to air conditioning.
(Cover Photo: Manhattan is shrouded in an afternoon haze seen from Staten Island in New York, U.S., June 23, 2025. /VCG)
