Dangerous heat and humidity ramp up across NJ, with spot thunderstorms too

The Bottom Line

The heat and humidity really ramp up Wednesday, as we stare down a ferocious heat wave that will last through the Fourth of July. An Extreme Heat Warning goes into effect for almost all of New Jersey at noon Wednesday, through Saturday evening. An Extreme Heat Watch covers the coast and far southern counties. Temperatures on Wednesday will reach into the 90s, Thursday will touch 100, and Friday will be in the 100s. Factor in the humidity, and the heat index could be close to 110 degrees — downright dangerous if you do not take care of yourself. While there could be a few late-day thunderstorms around late Wednesday and again on the Fourth of July, the heat is clearly the big story. It looks like rain and cooler air will move in early next week.

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Weather Hazards

Dangerous heat is the biggest headline and biggest concern here. An Extreme Heat Warning goes into effect for almost all of New Jersey at Noon Wednesday and will remain in effect until 8 p.m. Saturday evening. (That is the 4th of July.) An Extreme Heat Watch covers coastal and far southern counties. Daily high temperatures will reach the 90s and 100s, while the heat index may climb as high as 100 to 110 degrees at times. That is not normal, everyday summertime heat. That is dangerous heat, especially for anyone working outside, exercising, spending long stretches without air conditioning, or dealing with health issues.

Air quality is another concern Wednesday, with an Air Quality Alert (Code Orange) posted. Ground-level ozone may become unhealthy for the very old, the very young, and those with heart and lung issues.

There is also a moderate to high risk of dangerous rip currents at the Jersey Shore Wednesday.

And, while the heat is clearly the main issue, spot thunderstorms could develop late Wednesday and again Saturday. Any storm that forms in this hot, juicy atmosphere could produce downpours and gusty winds.

Climatological Context

July 1 is the 182nd day of 2026.

Normal high temperatures range from 85 to 86 degrees, while normal low temperatures range from 65 to 68 degrees.

July is, on average, New Jersey’s hottest and wettest month of the year.

Wednesday

Happy July! A month renowned for heat. And we have plenty of it in the forecast.

Temperatures Wednesday morning are mainly in the 70s across the Garden State. You will notice the difference stepping out the front door, compared to Tuesday. It is not comfortable anymore, as both heat and humidity really ramp up.

Wednesday will be hot and humid. Period, full stop. Expect mostly sunny skies and inland high temperatures in the mid 90s. The immediate coast will end up cooler, mainly in the 80s, benefiting from a sea breeze. But it will still be very warm and very humid.

There is an opportunity for spot thunderstorms to form, from late Wednesday afternoon into Wednesday evening. Most parts of New Jersey will not see a storm. But if one pops in your neighborhood, it could be on the strong side with downpours and gusty winds. The best chance of a storm will be in areas especially away from the coast.

Wednesday night stays clear, but muggy and uncomfortably warm. Lows will only fall into the mid 70s. Truly one of the worst parts of a heat wave is when the nights do not cool down much. That will be the case for the next several days and nights.

Thursday

Yeah, Thursday gets even worse. Downright dangerous heat and humidity on the way.

With nothing but hazy sunshine overhead, high temperatures will soar to near 100 degrees. Factoring in humidity, the heat index will approach 110 degrees. Nasty stuff.

Please make sure you have a plan to stay cool, stay hydrated, and stay safe, whether you are working, playing, traveling, or getting ready to celebrate the Fourth of July. Dress appropriately for the extreme heat and humidity. Take frequent breaks. Get into air conditioning whenever possible. And check on kids, seniors, pets, and anyone who may be especially vulnerable.

Friday

Friday will probably be New Jersey's hottest day of the week.

It will be mostly sunny and breezy. And that west-southwest breeze will counteract the sea breeze machine, meaning even the beaches will probably roast.

Most high temperatures on Friday will reach about 100 to 105 degrees. Again, the heat index — the “feels like” or “apparent” temperature — will probably top 110.

Records will be challenged. You will sweat like crazy. You will crave air conditioning, ice cream, and/or a nice cold beverage.

Just to be clear: I do not call heat extreme, intense, or dangerous unless it is truly warranted. New Jersey may be facing its hottest stretch of weather in almost four years. This clearly goes well beyond normal, run-of-the-mill summertime heat and humidity.

Saturday (4th of July)

That brings us to the 250th birthday of America — Saturday is the 4th of July. And the heat wave continues.

Saturday's highs will still be around 100 degrees. It may be a few degrees cooler than Friday, with some extra clouds in the sky. But still, it may end up being one of New Jersey’s hottest Independence Days in a long time.

For perspective, Newark Airport is usually one of the hottest weather stations in the state. The last time Newark hit 100 degrees or higher on the Fourth of July was 2010. My forecast for Saturday is 101 degrees.

There is also a chance for a few late-day thunderstorms Saturday. Nothing organized or prolonged is expected at this point, but a few pop-ups could interfere with your beach day, barbecue, parade, or even fireworks. (Hopefully, the timing and geography of those storms will become clearer as the holiday gets closer.)

Sunday & Beyond

Sunday stays steamy, with highs still in the 90s. Both the GFS and European models are now in agreement that scattered thunderstorms roll in Sunday afternoon, marking the beginning of the end of this heat wave.

Rain and cooler air look more likely early next week, a welcome change for sure. For now, my forecast shows high temperatures in the more seasonable, more reasonable 80s for Monday and Tuesday.

Until then, my message is simple: Take this heat seriously. The next four or five days are going to be brutal.

Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook for the latest forecast and realtime weather updates.