As the fierce week-long heat wave hits its fourth day, the heat index on Thursday could hit 105 degrees in parts of New Jersey with a chance of isolated thunderstorms in the afternoon and evening, though they won’t provide much relief.
The dangerous heat wave is likely to last through Monday before daytime highs finally dip below 90 degrees on Tuesday, forecasters say.
The National Weather Service has expanded a heat advisory to all 21 counties by adding Warren and Sussex counties to the list for Thursday. Residents are advised to take precautions and check on vulnerable neighbors.
New Jersey on average has had nine heat stroke deaths a year between 2000 and 2020 and heat-related hospitalizations typically peak during sweltering July heat.
All or parts of 13 counties are now under the advisory until 8 p.m. Sunday. Those counties are Bergen, northwest Burlington, Camden, Essex, Gloucester, Hudson, Mercer, Middlesex; Monmouth, Morris, Passaic, Somerset and Union.
The advisory in the rest of the state lapses (for the moment) at 8 p.m. Thursday. AccuWeather.com’s forecast for the heat index is even higher for New Jersey, topping 110 degrees.
High temperatures on Thursday will be well into the 90s in New Jersey, but the humidity will make it feel much worse, with heat index temperatures above 100 degrees.
The main change in the forecast for Thursday is that there’s finally a chance of rain in the afternoon, particularly in northern New Jersey, the National Weather Service said. The weather service says there’s a “slight” chance of precipitation elsewhere but notes most areas are likely to stay dry and sunny throughout the day.
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Record highs for July 21 are 103 in Newark (set in 2011), 101 in Trenton (1991) and 100 in Atlantic City (2019). Those numbers aren’t expected to be reached Thursday.
The weather service says Newark will get to 95 and Trenton will reach 97. A high of 90 is forecast for Atlantic City. The humidity, however, will make it feel much worse, with widespread heat indexes (how hot it feels when the humidity is factored in) above 100 degrees.
Warm conditions will stick around Thursday night with lows ranging from the upper 60s in northwest New Jersey to the low to mid 70s elsewhere, forecasters say.
The East Coast heat wave will continue through the weekend with temperatures in the 90s and humid conditions through Monday, according to AccuWeather.com.AccuWeather.com
Hot weather is forecast to continue through Monday, with Sunday expected to be the most oppressive of the weekend days. Highs will be in the 90s the next four days, with temps flirting with 100 degrees on Sunday.
Weekend evenings will also be muggy and uncomfortable, with lows falling into the 70s.
“Little in the way of relief at night,” the weather service said in its Thursday morning forecast discussion.
The heat wave is likely to end on Tuesday, though it won’t be cool by any means. Highs are expected to top out in the upper 80s.
Current weather radar
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Jeff Goldman may be reached at jeff_goldman@njadvancemedia.com.