New Brunswick, NJ

Following a hot and dry summer, the questions of the day in September were when the temperature would begin to cool and would more abundant rainfall arrive. Signs of a rainfall resurgence were mixed, with drought conditions diminishing in spots but worsening in others. The temperature answer came in almost a flash on the 22nd (the first day of astronomical fall!) when a powerful cold front sent the thermometer quickly downward with an early-fall-like pattern arriving and remaining through month’s end.

September temperatures averaged 67.8° across NJ. This is 0.9° above the 1991–2020 normal and ties as the 22nd mildest September since statewide records commenced in 1895. The average high temperature was 78.2°, which is 1.0° above normal and tied for 23rd warmest. The average low was 57.3°, 0.7° above normal and ranking 23rd warmest. North Jersey came in at 65.7° (+0.8°, tied for 23rd warmest), the south 69.0° (+0.9°, tied for 21st warmest), and the coast 69.7° (+1.0°, 15th warmest).

NJ precipitation averaged 3.16” for September, which is 1.00” below normal and ranks as the 57th driest of the last 128 years. The north was wettest at 3.64”. This is 0.82” below normal, though ranks as just the 67th driest. The south came in with 2.86” (-1.13”, 51st driest) and the coast 2.98” (-0.91”, 57th driest).

When it comes to recent hot Julys in New Jersey, the beat goes on. This year the heat was joined by quite limited precipitation, something not often seen in recent years. The statewide average temperature of 78.1° was 2.7° above the 1991–2020 normal, ranking 6th warmest since records commenced in 1895. Eight of the ten warmest Julys have occurred since 2010, leaving only 1955 and 1999 as top-ten outliers. The statewide average maximum was 88.6° (+2.9°, 6th warmest) and the minimum 67.5° (+2.4°, 4th warmest). Northern counties averaged 75.9° (+2.2°, 9th warmest), southern counties 79.5° (+3.0°, 3rd warmest), and coastal areas 78.8° (+2.6°, tied as 4th warmest).

Statewide July precipitation averaged 2.19”, which is 2.52” below normal, ranking as the 13th driest on record. Of the top 15, only two have occurred this century. The north averaged 2.03” (-2.69”, 14th driest), south 2.30” (-2.44”, 14th driest), and coast 2.16” (-2.22”, 17th driest). The central portion of the state was driest, with less than 2.00” accumulating, and under an inch in the driest areas. Closer-to-normal totals were found in the northwest, northeast, and southwest. At month’s end, portions of central NJ were classified as being in moderate drought (D1) on the weekly U.S. Drought Monitor map. This denotes conditions not seen more than once every five to ten years. Surrounding central and northern areas were considered abnormally dry (D0), as was the southeast corner of the state. This all coincides quite well with the most pronounced precipitation deficits of the past month.

Many across NJ wondered if the incessant back and forth of weather conditions from early spring into May would ever cease and the more consistent warmth of late spring would arrive and persist. It took time this year, with a cool, damp start to May that included a nine-day interval of almost continuous onshore easterly flow. Come mid-month the seasonal transition was finally complete, and daytime highs mostly remained above 70° away from the coast and higher elevations. This included two episodes where temperatures exceeded 90°. Whether it was cool or warm, rainfall was rather plentiful through most of the month. Seven events produced an inch or more at multiple locations, two of which found some spots exceeding 3.00”.

The statewide average temperature was 63.3°. This is 2.1° over the 1991–2020 normal and ties as the 14th mildest May since 1895. The average maximum of 73.6° was 1.3° above normal and ranked 35th mildest while the average minimum of 53.0° was 2.8° above normal, ranking 7th mildest. Regionally, the north division came in at 62.0° (+2.1°, 15th mildest), the south 64.3° (+2.1°, tied with two others at 13th), and coast 62.4° (+1.4°, tied with one other at 20th).

Rainfall averaged 5.37” across NJ. This is 1.62” above normal and ranks as the 23rd wettest May of the past 128 years. Even with the Highlands being somewhat dry, the north was wettest at 5.98” (+1.96”, 18th wettest). The south averaged 5.03” (+1.43”, 25th), despite the far south being on the dry side. The coast came in with 4.77” (+1.26”, 26th).

When it comes to shedding the winter coat and thinking of warm weather to come, March is known to have its early spring teases. Then, along comes some late winter cold to remind us winter is not quite ready to disappear. This spring foolery was on exceptional display this month. High temperatures jumped into the 70°s on the 6th and 7th, then back to the cold until the 70° mark was again eclipsed during four of the five days from the 15th–19th. Next came some more seasonable temperatures before a polar blast brought mid-winter frigid conditions from the 28th–30th, only to be followed by another day of 70°s to end the month. Interspersed with these wild fluctuations were episodes of thunderstorms, snow and rain, and 13 days where winds gusted to greater than 40 mph at some locations.

When all was said and done, the statewide average temperature of 43.6° was 2.6° above the 1991–2020 normal. This ranked as the 16th mildest March since 1895, with the end-of-month cold spell keeping the month out of the top 10 for warmth. The average maximum of 54.0° was 3.1° above normal, ranking 17th mildest. The average minimum of 33.3° was 2.1° above normal, also ranking 17th. The north averaged 41.1° (+2.3°, 21st warmest), south 45.3° (+2.9°, 15th), and coast 44.9° (+2.7°, 13th).

Precipitation averaged 2.72” across NJ, which was 1.48” below normal and ranks as the 26th driest March since 1895. The north caught 2.54” (-1.47”, 26th driest), south 2.80” (-1.52”, 30th), and coast 3.06” (-1.36”, 34th). In particular, a zone from Hunterdon to Bergen counties was driest and the coast from Atlantic to Monmouth counties was wettest.