Northeastern US Braces For Extended Heat Wave, Southeast Swelters In Steam

Hot and humid weather expected to persist, leading to increased energy demands and the need for cool environments.

<p><strong>Part of the New York city metro area will also experience its first heat wave of the summer, especially in the northern and western suburbs, which will be away from any cooling sea breeze. ACCUWEATHER</strong></p>

An extended period of hot and humid conditions is in store for the northeastern United States while the Southeast will remain in a steamy pattern for many days, AccuWeather meteorologists say.

The lengthy period of hot and humid weather is right on cue for early July. This pattern will make for some great days on the beach, at campsites and for outdoor activities that don’t require a great deal of physical exertion. The hot stretch will also lead to an uptick in energy demands as fans and air conditioners kick into high gear. Experts advise people to seek a cool environment when possible and to stay hydrated.

For some locations, such as Philadelphia, this will be the first heat wave of the year, where temperatures reach or exceed the 90-degree Fahrenheit mark for three or more consecutive days in a row. The temperature hit 90 on Monday in the City of Brotherly Love.

Part of the New York City metro area will also experience its first heat wave of the summer, especially in the northern and western suburbs, which will be away from any cooling sea breeze, AccuWeather Senior Meteorologist Matt Benz said.

“High temperatures in Manhattan’s Central Park, where the official records are kept for New York City, will range from the upper 80s to the lower 90s each day through at least Friday and will depend on the extent of the daily sea breeze,” Benz stated.

In Washington, D.C., where the historical average high is close to 90 degrees for much of July, temperatures hit 91 on Sunday and 92 on Monday.

“Because the 30-year average high temperature has crept upward in recent decades in the nation’s capital, the criteria for a heat wave should probably be more like the low to mid-90s for a heat wave, rather than the 90-degree threshold,” AccuWeather Senior Meteorologist Dan Pydynowski said. “But, hot is hot.”

Even if temperatures hit 90 or fall short of the mark, it likely will not matter all that much as AccuWeather RealFeel® Sun temperatures will be well into the 90s to near 110 for several hours during the afternoon hours. Light winds, high humidity and sunshine will be the driving force for RealFeel temperatures to be about 5-10 degrees higher than the actual temperatures.

The East experienced an unusually cold June before the sweltering weather arrived. In June, when temperatures are typically 3 to 8 degrees lower than in early July, temperatures from Boston, New York City, and Pittsburgh to Atlanta, Charlotte, and Charleston, South Carolina, averaged 1-4 degrees below the historical average. ACCUWEATHER

The hot and humid conditions are following an unseasonably cool June for much of the East. Temperatures from Boston, New York City and Pittsburgh to Atlanta, Charlotte and Charleston, South Carolina, averaged 1-4 degrees below the historical average during June, which is a time when average temperatures are 3-8 degrees lower than that of early July.

The weather in much of the Southeast will be typical of early to mid-July with plenty of heat, high humidity and intense sunshine.

A surge of heat at the end of June and at the start of July helped to prime residents and visitors in the Southeast for the stifling conditions.

A boater speeds along the Ross Barnett Reservoir in Rankin County, Miss., as residents seek ways to beat the heat, Friday, June 30, 2023. Hot weather brought dangerous and uncomfortable conditions to parts of the U.S. heading into a long July Fourth weekend. ROGELIO V. SOLIS/AP PHOTO

Temperatures in most locations will be several degrees lower through the weekend when compared to the highs ranging from the mid-90s to near 100 that were recorded last weekend.

The exception will be much of Florida, where temperatures will continue to be several degrees above average into this weekend. Widespread high temperatures in the mid- to upper 90s are forecast.

One thing that will be absent from much of the Northeast and parts of the Southeast this week will be a significant amount of wildfire smoke at lower levels of the atmosphere. Most of the thick and dangerous smoke from Canadian wildfires will be directed into the northwest U.S. and northern Plains this week.

While steering winds will be light, these breezes will be mainly from the south and southwest rather than the north and northwest. During much of June, northerly winds funned forest fire smoke directly southward from the Canadian province of Quebec, or by way of the Great Lakes region, and then into the East.

Some smoke from fires in western Canada may arrive late this week and this weekend. However, much of this smoke may tend to be at high and mid-levels of the atmosphere and be noticeable in the form of hazy sunshine. Any northerly breeze that develops during the summer could bring thick low-level smoke from the fires burning in Quebec back into the Eastern states.

In terms of rainfall, the heat and moisture can lead to pop-up thunderstorm activity just about any day in the Southeast through the weekend.

As most long-time residents know in the Southeast, these “garden variety” storms can be rather intense for a short time with loud claps of thunder, gusty winds and torrential downpours.

On Wednesday, Thursday and part of Friday in the Northeast, thunderstorms are likely to be few and far between.

However, as a slight dip in the jet stream pivots from the Midwest, thunderstorms are likely to erupt over the central and northern Appalachians on Friday afternoon and may survive to the Interstate 95 corridor Friday evening. It is highly likely that most of the beaches will stay dry through Friday and may not see much rain – if any – through Sunday afternoon.

From late this weekend into next week, the jet stream will take a more general shift southward and may be able to scoop up extra moisture from the Gulf of Mexico. This scenario would likely lead to slightly lower temperatures, high humidity and perhaps more prolific thunderstorm activity throughout the Eastern states.

Produced in association with AccuWeather