New Brunswick, NJ

The summer of 2018 concluded on a warm, wet note across the majority of what was a persistently green Garden State throughout the season. The warmth dated back to late June, with frequent humid conditions and abundant showers from mid-July onward. There will be more on the entire summer at the end of this report. First a look at August, with a statewide average temperature of 76.8° coming in 3.8° above the 1981–2010 average. This was the second warmest August since 1895, falling just behind 2016 by 0.1°. Nine of the 13 warmest Augusts during that 124-year interval have occurred since 2001.

Statewide, August precipitation averaged 5.63”. This was 1.53” above the 1981–2010 average and ranked as the 32nd wettest since 1895. It was the wettest August since the record wettest month in 2011. As is often seen in the summer, the majority of the precipitation fell in scattered showers and thunderstorms. This resulted in a wide range of monthly totals around the state, with some serious flash flooding occurring in several locations when moisture-ladened storms parked themselves over an area for multiple hours. Where storms missed time and time again, rainfall totals were below average. The northern NJ climate division (Hunterdon, Somerset, and Union counties northward) saw their 10th wettest August on record, with an average of 8.28” falling. This is 4.17” above average. Since 1990, only August 2011 was wetter in this division.

After an ample share of ups and downs throughout the past spring, the weather in June became rather typical for the start of summer. It was drier than average in the north and wetter than usual in the south, with the temperature close to the long-term mean. Fortunately, New Jersey entered the heart of summer with reservoirs full. However, with the onset of an apparent extended period of heat late in the month, it is certainly prudent to conserve water wisely.

The June average statewide temperature of 69.8° equaled the 1981–2010 mean, but is 1.0° above the 1895–present average. This tied with 1906 and 1967 as the 42nd mildest June on record. Precipitation averaged 3.43” across NJ, which is 0.58” below the 1981–2010 mean. This ranks as the 57th driest June, tied with 2011.

If you think it has been a long time since New Jersey experienced as chilly an April as this past one, you are correct. With snow accumulating in a storm on the 2nd to snow showers on the 30th, one was hard pressed to find many days when pleasant spring conditions could be found. Toss in two mid-month days when temperatures soared into the middle 80°s and another with strong thunderstorms delivering flash flood-producing rains, and weather-oriented heads kept spinning. However, overall, it was the persistent chill that captured the most attention, with the green up of lawns and foliage, accompanied by the blossoming of spring flowers, delayed from normal by upwards of two weeks.

Statewide, the April average temperature of 47.7° was 3.2° below the 1981–2010 mean (2.0° below the 1895–2017 mean). This ranks as the 28th coolest April since 1895 and the chilliest since 1982 (also 47.7°). The highest temperature observed in NJ was 87° at Stewartsville (Warren County) on the 14th and the coldest 16° at Walpack (Sussex) on the 11th.

April precipitation across NJ averaged 4.20”. This was 0.21” above the 1981–2010 mean (0.48” above the period-of-record mean). This was the 38th wettest April on record. Plentiful precipitation since February has eliminated drought concerns as we enter the summer water consumption season. Reservoirs and ground water levels are in good shape. However, this never means we should let our guard down and not use water in a responsible manner.

While the title of this report is guilty of some exaggeration, by just looking at the temperatures across New Jersey the past two Februaries you would not be far off the mark. The mildest February by far occurred in 2017 (40.4°), while this past February 2018 came in second mildest at 39.2°, just edging out 1998. This was 5.8° above the 1981–2010 mean and an impressive 8.3° above the 1895–present mean. The difference between mean periods further illustrates how Februaries in recent decades have been milder overall than earlier in the 20th century. So does the fact that February 2018 was milder than 62 of the past 123 Marches (February 2017 was milder than 70 Marches).

Not to be ignored due to February’s warmth, monthly precipitation certainly delivered in an impressive manner. The average statewide rainfall of 5.97” ranks as the third wettest on record. This is 3.17” above the 1981–2010 mean (2.87” above the period of record mean) and is the wettest February in well over 100 years.