Deadly Northeast heat wave to peak on Sunday

The most intense and long-lasting heat wave so far this summer is already well underway in the Northeast. AccuWeather forecasters say the region's hottest weather so far this season for many will arrive on Sunday.

Intense heat first began for much of the Northeast and mid-Atlantic last week when temperatures soared above normal levels during the hottest part of the summer. Residents across the region sweltered and struggled to keep cool to end the week while the heat became deadly in two states.

At least two people succumbed to the scorching conditions last week. On Thursday, officials in Allentown, Pa., said a 73-year-old man became the city's first heat-related death this year according to NBC10 Philadelphia. The Lehigh County Coroner's Office said that the man "suffered from excessive heat exposure, complicated by underlying medical conditions."

On Saturday, the New York City Medical Examiner's office said that a resident succumbed to heat exposure, according to the New York Post. While few details were given, the office stated that the person also suffered from underlying conditions.

Several major metros along the Interstate-95 corridor have put excessive heat measures into effect in an effort to keep residents cool and safe. In Washington, D.C., Mayor Muriel Bowser announced on Thursday that a Heat Emergency was active through Monday, allowing shelters and cooling centers to open.

In Philadelphia, Mayor Jim Kenney also enacted a Heat Health Emergency from Thursday through Sunday. During this emergency, cooling centers and Septa cooling buses are available to the public.

Intense heat from the past week continued to bake the East Coast on Saturday as high temperatures above 90 degrees Fahrenheit were quite common.

Washington, D.C., reached 96 degrees on Saturday, making it the sixth straight day and eleventh day in July that the nation's capital eclipsed the 90-degree mark. Farther north, the heat reached even more extreme levels. Philadelphia surged to 98 F on Saturday, which is 10 degrees above average for the date.

Some of the highest temperatures of the day were observed in the greater New York City area. While the city itself topped out at 95 degrees, the mercury just to the west in Newark, N.J.,, reached a scorching 101 F. This reading in Newark fell just 1 degree shy of the record for the date set in 2011. Saturday was also the fourth straight day that Newark reached or exceeded the century mark, which is 13 degrees above normal for this time of year.

In New England, sweltering heat was just as easily found. Boston climbed into the 90s for the fifth consecutive day, topping out at a high of 94 F. This reading was 12 degrees above normal for the date. Roasting weather was even found in Maine, with Bangor reaching a toasty 92 degrees.

Saturday was one of the hottest days of the year for many across the northeastern United States, but Sunday will be even more intense, forecasters say.

Heading into Sunday, temperatures for many are expected to nudge even a few degrees higher. Due to the urban heat island effect, where buildings and other paved surfaces trap heat efficiently and raise temperatures, some of the hottest weather will be found in the cities along the densely populated Interstate-95 corridor.

"While locations well to the west may see some cloud cover and cooler thunderstorms, it will be dry and mainly clear along the Eastern Seaboard, which will allow temperatures to quickly surge beneath the heat dome that is in place," AccuWeather Senior Meteorologist Mike LeSeney said.

Washington, D.C., and Philadelphia are both forecast to be within a degree or two of the century mark, which would only narrowly fall short of the daily record highs in those locations.

Similar to recent days, conditions will be very hot, but a bit variable in the New York City metro area. While the city itself is predicted to peak at 96 F on Sunday, the frequent hot spot in Newark is slated to reach a scorching 103 degrees, which would shatter the record for the date of 99 set in 2010.

Much like in recent days, the heat will extend even farther north.

As of early Saturday afternoon, Boston had already tied its record high temperature for the day of 98 F, which was last set in 1933, with several more hours of peak daytime heating to go.

Hot weather will even extend as far north as Canada and northern Maine. Fredericton, New Brunswick, which is located approximately 320 miles northeast of Boston, is forecast to reach a highly abnormal 92 degrees Fahrenheit on Sunday. High temperatures for late July are typically near 75 F, or 24 C.

In Caribou, Maine, the state's northernmost city, a high near 90 degrees is forecast for Sunday. If the mercury tops out at this level, it would be the first time since Aug. 26, 2021, that the city reaches that threshold.

While the high temperatures may be most eye-catching and will feel the most scorching for those outside, in the heat, it is actually the low temperatures that are most dangerous to those prone to heat-related illnesses, especially those without access to air conditioning.

"Temperatures Sunday night will only bottom out in the upper 70s or even low 80s in the warmest spots. For those who are most susceptible to the heat, this makes it extremely difficult to cool down at night, which is a major cause in heat-related illnesses and deaths," LeSeney said.

Fortunately, however, relief may come sooner rather than later, thanks to an approaching storm system. On Monday, a cold front sweeping toward the coast will spawn showers and thunderstorms for much of the East Coast. While some storms could turn severe, temperatures may drop as much as 10 degrees from Sunday to Monday along the Interstate-95 corridor before falling even more on Tuesday.