FiOS1 News Weather Forecast New Jersey. Sunny skies this afternoon with temperatures in the mid to upper 70s. Much cooler air is going to arrive tonight with lows in the 50s. Some 40s in cool spots in Western New Jersey. Sunshine with some arriving clouds on Monday with highs in the low to mid 70. Tuesday mostly cloudy skies and cool with highs in the upper 60s shore..some mid 70s inland and west.