Extreme heat and high humidity are expected across more than half the country as the calendar officially marks the beginning of summer on June 21.
In the D.C. area, temperatures later this week should start climbing into the 90s, and hold there for several days.
The mid-Atlantic region and Eastern Seaboard, along with the South and Midwest, could be in for some unpleasant weather in the coming days.
National Weather Service meteorologist Bob Oravec said water temperatures in the Gulf of Mexico and parts of the Atlantic are heating up and that’s fueling the hot, humid weather that much of the country will experience in the coming days, and likely last through the Fourth of July.
“They don’t last forever,” he said. “The pattern we had was pretty persistent, but now it’s changing to another pattern and it’s going to be more summer like.”
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That means midday temperatures in the upper 90s and very high dew points, fueling the humidity.
“There’s a big dome of high pressure that’s going to start building east of the Rockies,” said 7News First Alert Chief Meteorologist Veronica Johnson
That will make for above-average temperatures in D.C. as well as other major cities, such as Chicago, Detroit and St. Louis. This time of year, the average temperature in D.C. is 85 degrees.
Looking at the 10-day forecast, Johnson said Friday is the only day when temperatures are forecast in the 80s. Most days, temperatures are expected to be 95 degrees or hotter.
“Just looking at what the weather pattern looks like for next week, there will be some major to extreme heat stretches across large parts of the Eastern United States,” Oravec said, pointing out how the weather will impact as many as 170 million people from as far west as Nebraska to the Atlantic Ocean.
Summer heat may have been slow to arrive to the D.C. area this year, but once it’s here, it will be sticking around for a while.
“What’s surprising is the fact that it has been so cool with that ‘first 90’ occurring so late,” Johnson said. “Out of 153 years of records, it was our ninth latest ‘first 90.'”
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If you plan to exercise outside, Oravec said do it early in the morning, not at 2 p.m. during the hottest part of the day.
“There will be times of the day when people should not be outside, or at least not doing a lot of activities into the late morning and into the afternoon,” he said.
Veronica Johnson said the D.C. area has flipped the switch into summer.
“It is looking like what I call the high octane kind of air when it is filled with some very high humidity levels, and that is what takes a toll on so many of us, the elderly, the young,”
The moisture in the air can negatively impact the air quality and make it challenging for people to breathe or cool down in general.
“But that high humidity … makes it that much harder to cool off, hard to have any evaporative cooling take place where the air is filled with humidity, our bodies just can’t cool.”
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