NYC faces longest stretch of 90-degree temperatures in nearly a decade
A major heat wave is set to take over the Northeast, AccuWeather forecasters warn, and it is expected to bring the longest stretch of 90-degree days to New York City in nearly a decade and a similar stretch of 90-degree weather to Philadelphia.
The heat also transferred northeast of New York City to Boston, where Tuesday's temperatures set a year-high in the city, hitting 93 degrees. The city's previous high was set on July 1 at 92.
Unlike many other parts of the nation, summer across much of the Northeast has been largely normal in terms of high temperatures, even mild at times. However, that began to change dramatically Tuesday as high temperatures soared in the wake of a round of disruptive thunderstorms that tore across the region a day earlier.
In New York City, the lengthy heat wave could be the longest in nearly a decade. The last time New York City strung together seven consecutive days with highs of 90 or greater was July 14-20, 2013. The Big Apple is predicted to do just that as AccuWeather is forecasting high temperatures there to be 90 or higher on every day through Monday, July 25. Tuesday's high hit 90 in the city, planting the hub firmly into the scorching heat.
The record for the city's longest heat wave, which was 12 days, spanned Aug. 24 to Sept. 4, 1953, at Central Park, the city's official site of weather records.
The National Oceanic and Atmospheric Administration (NOAA) defines a heat wave as "a period of unusually hot weather that typically lasts two or more days" and also notes that, in order to qualify as a heat wave, "temperatures have to be outside the historical averages for a given area."
In the Northeast, meteorologists typically define a heat wave as at least three consecutive days on which high temperatures reach 90 F or greater.
Both New York City and Boston typically have about a week's worth of days with highs of 90 or better by the middle of July. The Big Apple has been on track with this through July 17, but Beantown had tallied only two days of 90-degree weather until Tuesday's year-high.
Washington, D.C., has picked up 14 days with 90-degree heat as of July 19, which is a few below the average of 16. Tuesday added to the tally, hitting a high of 92.
All locations in the Interstate 95 corridor from Virginia to Massachusetts will significantly add to their number of 90-degree days this week and perhaps right through next week. Temperatures will average 5-10 degrees above normal, following near-average temperatures for most days since early June. On Tuesday, metro areas in the states hit the 90-degree mark, including Richmond rising to a high of 92.
Philadelphia, which has been the most successful at stringing hot days together this summer, will likely rack up seven or more days in a row of 90-degree temperatures. Philadelphia has amassed four days in a row of 90-degree highs two separate times so far this summer. Tuesday's high followed the heat trend in the city, sweltering to 93 in the late afternoon.
Neither Boston nor Washington, D.C., has experienced an official heat wave so far this summer, but New York City had one from July 12-14.
Philadelphia and Washington, D.C., have the potential to string 90-degree highs each day through this weekend and beyond. This would give Washington, D.C., its first heat wave of the summer. Boston also could sneak in with as many as five 90-degree days in a row this week.
Some daily fluctuation in temperature is possible and most likely across the Appalachians. Meanwhile, sea breezes most days will help keep the heat at bay along most beach communities.
During the pattern, which may last through next week, many locations have the potential to record their highest temperature of the year so far. Tuesday broke Boston's year-high, while New York City hit 93 back on May 31. Washington, D.C.'s current high for the year is 99 degrees and was set on June 17.
Typical humidity levels for the second half of July will accompany the heat on most days.
The combination of heat, high humidity, sunshine and other factors will push AccuWeather RealFeel® Temperatures to levels equivalent to 5 to 15 degrees higher than the actual temperature.
As temperatures climb to hot levels in the major cities for multiple days in a row, conditions will lead to nights full of uncomfortably warm and humid conditions. Concrete, asphalt and brick structures will tend to give off the heat for many hours after dark.
Experts urge people to drink plenty of fluids and avoid strenuous exercise or physical labor when RealFeel® temperatures are typically highest, which is usually during the midday and afternoon hours. Failure to do so could lead to heat exhaustion or heatstroke, no matter how physically fit an individual is. People should seek an air-conditioned environment when possible and closely monitor young children and the elderly, who are more prone to heat-related illnesses than the general population.
The period from July to mid-August is often the hottest time of the year for much of the U.S. and the Northern Hemisphere, but the term "dog days of summer" originated from the appearance of the dog star "Sirius" during ancient times during the same part of the summer.
Despite the number of 90-degree days on the way, only a few daily high-temperature records are likely to be broken, forecasters say. However, following some showers and thunderstorms, it is possible that as the ground dries out later this weekend and early next week, a few daily records may be challenged.
A dip in the jet stream will still help safeguard the region from long-lasting surges of 100-degree heat that have been so persistent this summer over the South Central states and more recently contributing to the unprecedented heat in western Europe. In both cases, it is a northward bulge in the jet stream that has been producing excessive heat.
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