News

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.

With the Northern Hemisphere atmosphere transitioning from winter to spring, March can be a month of frequently-changing weather with pronounced pressure gradients, thus punctuated by windy conditions. This past March was no exception, and in fact, a windier month would be difficult to find. Winds gusted to 50 mph or greater at one or more NJWxNet station on 11 days and between 40–49 mph on four other days. At most locations, the warmest daily average temperature of the month was, of all things, on March 1st, while the first 80° day of the year was on the 25th. In between those warm spells was the largest snowstorm of the year in central and northern locations and two weeks of some of the coldest weather of the winter. Finally, March went out like a lion, with a statewide soaking rainstorm on the 31st.

The statewide monthly average temperature of 38.9° was 1.9° below the 1981–2010 average. This ranks as the 61st coldest of the past 123 Marches. It was the first month with a below-average temperature since last May, which was only 0.3° below average and last April with a 0.1° negative anomaly. While not exceptionally cold, due to the record warm February average of 40.1°, this was only the third time on record when March was colder than the previous February. This occurred previously in 1984 and 1960. The 1960 occurrence was mainly due to March being the second coldest on record, while in 1984, February was 9th mildest and March 10th coolest. On average, March is 7.3° warmer than February. While the cold of March damaged blossoms of some prematurely-blooming trees and flowers, vegetation was not far enough along to result in significant problems.

A progressive weather pattern dating back to last fall continued to hold serve across the eastern US in January. This resulted in temperatures swinging between mild and cold levels and unsettled weather systems moving through often enough to bring precipitation levels close to average but, with one notable exception, not staying around too long to wreak havoc. Overall, it was a mild month, with a statewide average temperature of 36.2°, which is 5.5° above the 1981–2010 mean. This ranks as the 12th mildest January since 1895. It is interesting to note that while 10 of New Jersey’s warmest 15 years have occurred since 2000 and 14 of 15 since 1990, Januaries have not as often kicked off these warm years as much as one might imagine. Only 5 of the 15 mildest Januaries over the 123 year record have occurred since 2000 and just 8 of the 15 mildest since 1990.