New Brunswick, NJ

Even in a rather tranquil month, there are always interesting aspects of New Jersey’s weather and climate that can make for memorable situations. Such was the case during the 11th month of 2017. On the heels of a mild October and first week of November came one of the coldest early-season blasts on record on the 11th. Then the 19th saw some of the strongest winds of the year across the state. Overall, dry conditions by month’s end put the northern Highlands in the D0 (abnormally dry) category on the US Drought Monitor map, threatening to expand further into the state should dry conditions persist.

Rainfall averaged 1.68” across the state. This is 1.93” below the 1981–2010 mean and ranks as the 19th driest November since 1895. It was the driest since 1.30” fell in 2012 and well above the record low 0.54” in 1917. The statewide average temperature of 44.3° tied with 1938 as the 75th coolest (or 49th mildest) on record. The average was 0.9° below the 1981–2010 mean, but 0.8° above the 1895–2017 mean. This demonstrates how New Jersey has warmed in recent decades compared to earlier in the 20th century.

While remarkable deadly and destructive hurricanes pummeled portions of the Caribbean and southern states, September weather conditions in the Garden State were generally quiet. The most notable exceptions were the dangerous rip currents at the Jersey shore associated with the latter stages of Hurricanes Irma and Jose, which resulted in several drowning deaths and numerous water rescues. Minor to some moderate back-bay flooding and beach erosion accompanied the tumultuous surf, particularly between the 18th–21st. Otherwise, little more than some clouds and light rain reached NJ from these storms, while earlier some remnant energy and moisture from Hurricane Harvey brought one of the month’s few notable rain episodes. Dry conditions prevailed through much of the September, especially the second half. As a result, statewide precipitation averaged just 2.23”. This is 1.82” below the 1981–2010 average and was the 28th driest September since 1895.

While the first half of the month had an average temperature of about a degree below normal, September finished on a warm note. Some locations experienced three consecutive days with maximums of 90° or higher from the 23rd–25th. This backwards turn to warmth while the calendar suggested there should be a decline in temperature resulted in the month averaging 2.6° above the long-term mark. The 68.4° average made this the 10th warmest September on record. The last three Septembers and six since 2005 all fall into the top 10.

July 2017 proved to be an active month of weather throughout the Garden State. Time and time again, storms traversed the state, often depositing the heaviest rainfall in 30–40 mile west-to-east “corridors,” while elsewhere totals were much lighter. Such is the nature of showery summer rainfall, although in one case, the swath of heavy rainfall was associated with an out-of-season coastal storm. When all was said and done, rainfall occurred frequently enough to leave most locations with average to well above average monthly totals. The statewide average July rainfall was 6.33”. This is 1.76” above the 1981–2010 average and ranks as the 19th wettest July of the past 123 years. Last year with 6.97” (ranking 13th) and 2004 with 7.51” (ranking 8th) were the most recent Julys to be wetter than this year. The statewide average temperature of 75.5° was 0.9° above average. This ranks as the 22nd warmest July on record. There have been nine warmer Julys since 2002, including last year at 77.1° (ranking 7th).

It is always comforting to enter the water demand season, namely summer, with a bit of a hydrological cushion. Such is the case this year across NJ, thanks to ample rain and some late-season snow in recent months. This timely precipitation has eliminated drought concerns that stemmed from drier-than-normal intervals during 2016. As a result of the precipitation deficits, ground water, streamflow, and reservoirs all dropped to precarious levels, thus the issuance last fall of a drought warning by the NJ Department of Environmental Protection over northern NJ and a drought watch in some southern counties. Aside from two reservoirs in west central NJ remaining below average, at the moment all other hydrological signs are positive. However, no one should let their guard down and fail to appreciate the finite nature of our fresh water resources, and how quickly a period of abundance can lapse again into drought.

More will be noted regarding spring (March–May) conditions later in this report. First taking a look at May, New Jersey experienced its 9th wettest on record, with observations extending back to 1895. The statewide average rainfall of 6.62” was 2.63” above the 1981–2010 average and the wettest May since 1990. Frequent clouds and rain resulted in many chilly days, however, a mid-month heat wave was impactful enough such that the average statewide temperature of 59.8° was only 0.7° below the 1981–2010 average. It was the 61st coolest May of the past 123 years, with none cooler since 2008.