Highs will reach into the 90s again Friday, with a heat index near 100 degrees. At least that will allow overnights to cool slightly, knock down the daily storm chances, and kick the heat index out of the danger zone. Get our free mobile appWeather HazardsA Heat Advisory continues for most of New Jersey until 8 p.m. Saturday. The heat index — the summertime “feels like” or “apparent” temperature — will be close to 100 degrees for most of Friday. With the humidity, the heat index will end up close to 100 degrees.