The Future of Summer Is Getting Hotter. Here’s Why Heat Domes Are Becoming More Frequent.
A long heat wave is bearing down on the eastern United States in the coming days, while the Southwest has already been pushing temperatures near 100 degrees Fahrenheit (38 Celsius) this week. The driver behind this kind of punishing, prolonged heat is something meteorologists call a heat dome, and right now, one is also baking much of Europe under highs near 40 Celsius (104 Fahrenheit).
With temperatures expected to spread across more of the country by the Fourth of July holiday, and with more than 180 million people facing “major” or “extreme” heat risk on the eastern half of the U.S., understanding what a heat dome is, and how to survive one, has become an urgent summer question for households, schools and emergency rooms alike.
How a heat dome actually forms
A heat dome is essentially a massive, stubborn high-pressure system that parks itself over a region and traps hot, humid air underneath. It forms when warm air flows northward, sinks toward the surface and increases atmospheric pressure, which pushes temperatures up and keeps skies dry and sunny for days at a stretch. Because these systems move slowly, they can sit in place until another weather pattern shoves them out of the way. The result is heat that builds, amplifies and refuses to break, often setting records on the way.
“So what a heat dome really is, is a big high pressure system. So, here in the United States or in other portions of the world, we’re used to these during the summer. But this one is really, really intense. It’s a really strong high, which is leading to very, very warm temperatures through across the vast majority of Europe. High pressure systems like this heat dome tend to be in a situation where they’re not moving quite as fast, and so they tend to kind of sit over areas for long periods of time if there’s not another storm system to kind of nudge it out of the way. And so this is leading to those really, really warm, record-breaking temperatures across almost all of Europe, but especially the western half,” Dr. Erik Nielsen of Texas A&M University told Campus Insights Media.
Where heat domes are hitting hardest in 2026
This summer’s extreme heat is not isolated to one region. The continental U.S. just logged its most abnormally hot March in 132 years of record-keeping, with record-shattering temperatures showing up first in the Southwest and then rippling across the rest of the country. Europe has been broiling under unseasonable highs starting in mid-June, all of it tied to a heat dome locked in over the continent.
The heat is also reshaping how organizers think about major events. Extreme temperatures are top of mind for the upcoming World Cup, which will be played across the U.S., Canada and Mexico, three countries already grappling with their own heat patterns this year.
Health risks and how to stay safe
Heat domes are dangerous in part because they don’t ease up at night, which makes it difficult for the body to fully cool down and recover. According to the National Weather Service, emergency room visits for heat-related illness surge on days rated “major” (Level 3) or “extreme” (Level 4) risk. Right now, more than 180 million people across that same swath of the country are inside that risk zone, and finding ways to stay cool during both daytime and evening hours becomes essential.
Experts say preparation matters most for people who don’t usually deal with this kind of heat.
“So if this is your first time experiencing some of this sort of heat, you really have to kind of go in and plan your day to not be out in the heat of it, because once you’re out and once you’re warm, you’re not going to be able to cool as efficiently, especially if you don’t have a place that has cooled air or that sort of place to come back to,” Nielsen told Campus Insights Media.
He added that local adaptation makes a real difference. “I think it’s important to understand that places aren’t necessarily prepared for the same sort of weather threats, right? We in the Southern U.S. are used to hot, humid climates. The northern portions of the U.S. are not maybe as used to that. The same thing goes for international locations, right? They have, they’re used to kind of their local climate and you adapt accordingly. And so when something that is outside of the realm of being normal happens, that’s where you start running into problems.”
The climate connection
Scientists say these increasingly intense heat domes are not random. Jennifer Francis, a climate scientist at the Woodwell Climate Research Center, points directly at fossil fuel emissions and deforestation as the engines behind the trend.
“Heat waves like this are so directly connected to the climate crisis and climate change and it’s because of how we’ve been burning fossil fuels and cutting down forests for so long and increasing the concentration of heat-trapping gasses in the atmosphere,” Francis told AP.
“These kinds of heat waves and droughts and associated fires are all increasing just as we would expect them to in a warming world,” she added.
The video Extreme European weather — what is a heat dome featuring Texas A&M University instructional associate professor Dr. Erik Nielsen was first published on Campus Insights Media.
The video Extreme European weather — what is a heat dome featuring Texas A&M University instructional associate professor Dr. Erik Nielsen was first published on Campus Insights Media.
This article was created by content specialists using various tools, including AI.
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