A heat dome is baking half the country as Europe’s deadly heat wave grinds on

A heat dome is settling over the eastern half of the United States this week, bringing the region’s most widespread heat wave of the summer so far. The dome is building in response to a major shift in the jet stream that’s also driving a sharp cooldown and dangerous fire weather in Utah, Colorado and Arizona, where a large, destructive fire is already burning.

Heat and humidity are expected to intensify across the South before expanding north into the Midwest and Great Lakes, with the Northeast, including New York City, Pittsburgh and Washington, D.C., growing increasingly hot and humid by midweek. Forecasters expect highs in the upper 90s to near 100 degrees across a large stretch of the South, with the low to mid-90s common in the Midwest, Mid-Atlantic and Northeast.

The pattern has already triggered extreme heat warnings in parts of the Upper Midwest, including Minnesota, where heat index values climbed close to 110 degrees Monday. It’s a preview of what’s headed toward the rest of the region this week.

This wave isn’t expected to rival the record-breaking extremes seen in Europe last week or in the western U.S. in March, but forecasters say it will be scorching for days and no less dangerous, arriving just as the central and eastern U.S. enter their usual hottest stretch of the year.

That context matters because Europe’s heat wave has turned lethal. More than 1,300 deaths across the continent have been linked to the extreme heat, with France alone recording roughly 1,000 additional deaths during the height of its record-smashing heat, concentrated especially around Paris.

Météo-France said June 23 was the country’s hottest day since record-keeping began in 1947, with temperatures reaching 44.3 degrees Celsius. Records also fell in Germany, Switzerland and Denmark over the weekend, with Germany hitting a high of 106 degrees Fahrenheit.

Forecasters attribute the stubbornness of the European event to an “Omega Block” weather pattern that has trapped a stagnant mass of dry Saharan air beneath a locked-in heat dome. The core of that dome has since shifted toward Germany, Poland and the Baltics, with national weather services from Berlin to Prague issuing red alerts for extreme fire danger, and no significant disturbance is expected to break the pattern before July arrives.

Climate scientists tie the back-to-back extremes on both continents to a broader trend: heat waves worldwide are becoming more frequent and severe because of human-caused warming from fossil fuel pollution.