Summer

It is not as if August 2023 was devoid of strong thunderstorms that produced locally heavy rain and three minor tornadoes. There were also some hot and humid days and even a few days with smoke high aloft, a rather persistent feature of this summer’s weather (more on this in earlier June and July recaps and the summer summary later in this report). However, with temperatures a bit below normal and statewide rainfall leaning that way too, it just was not a particularly notable August in the weather/climate department. Mind you, most folks hardly complained of 90° maximum temperatures being rather scarce, there being no soaking tropical system, and, for the most part, fine weather for outdoor activities.

Statewide, the average temperature of 72.9° was 0.7° below the 1991–2020 normal. This ranked as the 48th warmest August of the past 129, but the coolest since 2017. Three of the past four months have been below normal, something not accomplished since January, March, and April 2018. The average high of 82.4° was 1.4° below normal, ranking 60th warmest. The low of 63.4° was 0.1° above normal, raking 31st warmest. The northern climate division averaged 70.7° (-1.2°, 53rd warmest), the southern division 74.2° (-0.4°, 46th warmest), and coastal division 74.5° (-0.2°, 38th warmest).

Precipitation averaged 4.03” across NJ, which is 0.54” below normal and ranks as 61st driest (68th wettest) since 1895. There was a north/south difference in rainfall, with the north averaging 5.02” (+0.46”, 41st wettest/89th driest), the south 3.45” (-1.12”, 49th driest/81st wettest), and coastal NJ 3.14” (-1.46”, 42nd driest/88th wettest).

Much like this past July, August was a hotter and drier month than normal. Despite a June with rather close-to-normal numbers, the two most recent months brought the summer temperature and precipitation to top-10 levels for hot and dry conditions. More on summer ’22 later in this report, but first to discuss is a record hot and quite dry August.

The August average temperature of 77.4° was 3.8° above the 1991–2020 normal, ranking as the hottest on record. Eight of the ten warmest Augusts since 1895 have occurred since 2001. The average maximum of 88.5° was 4.7° above normal, the hottest on record, while the average minimum of 66.2° was 2.9° above normal, tied for 5th warmest. North Jersey averaged 75.7° (+3.8°, warmest on record), the south 78.4° (+3.8°, warmest on record), and the coast 77.9° (+3.2°, 3rd warmest).

Statewide, August precipitation averaged 2.61”, which is 1.96” below normal, ranking as the 22nd driest. The north came in at 2.31” (-2.25”, 18th driest), south 2.82” (-1.75”, 29th driest), and coast 2.54” (-2.06”, 25th driest). As the map shows, virtually the entire state had a monthly total below the statewide 4.57” normal. Exceptions were found in isolated west central and central coastal areas where several storms quickly deposited hefty totals. Less than half the normal monthly rainfall fell in a good portion of the north and in scattered areas of the south and north coast.

As reported multiple times during the first half of 2022, the day-to-day weather and overall climate of the Garden State have varied frequently, exhibiting lots of variability and never “locking” into a given pattern for an extended period of several weeks or longer. Such was the case this June, making it difficult to define any conditions that dominated. June was somewhat drier than average, but eight events brought over an inch of rain somewhere within the state. It was also dry enough at one point for a wildfire to scorch over 13,000 acres of the Pine Barrens. Low temperatures fell into the upper 30°s and low 40°s at multiple locations on the 20th, yet three days earlier, the majority of the state saw highs in the low to middle 90°s. “Non-descript” seems the best way to sum things up.

Statewide, rainfall averaged 3.44”. This is 0.86” below the 1991–2020 normal and ranks as the 61st driest of the 128 Junes since 1895. The north received 3.59” (-1.02”, 61st driest), the south 3.39” (-0.75”, 61st driest), and coast 2.90” (-0.95”, 54th driest). As the map shows, the far south was driest, continuing a pattern seen in recent months. The June 30th U.S. Drought Monitor map has the bulk of the southern area seen on the Figure 1 map receiving less than 4.00” for the month classified as “Abnormally Dry” (D0). This rating is also a function of both low streamflow and ground water levels. Further north, pockets of above-average rainfall surrounded a below-average central region that has yet to have prolonged enough water deficits to qualify for D0 status.

Wow, what a month. July 2021 provided a never-ending cascade of weather events, including a tropical storm, a record-tying number of tornadoes, large hail, flash floods, hot days, chilly nights, smoke-filled skies, and on the last day of the month, perhaps the nicest day of the summer. The statewide average precipitation of 7.59” was 2.88” above the 1991–2020 normal and ranked 8th wettest of all Julys back to 1895. It was the wettest July since 1975 and second wettest in almost 50 years. The northern portion of the state averaged 8.16” which was 3.44” above normal. The south averaged 7.36” which was 2.62” above normal.

The average temperature of 75.8° was 0.4° above the 1991–2020 normal, but 1.9° above the 1895–2021 average. This ranked as the 24th warmest July since 1895. 13 of the 25 warmest Julys in the past 127 years have occurred since 2002. The nine July tornadoes is the most in a month since official records began in 1950. Tropical Storm Elsa was the earliest fifth storm of any season on record in the Atlantic basin. Read on for details on this potpourri of weather happenings.

August joined the chorus of much warmer-than-normal months experienced throughout most of 2020 to date across the Garden State. Six of the eight months have ranked among the top 10 warmest for the 126 years beginning in 1895. Only April and May are outliers and, in fact, each of them had below-average temperatures. With a mean of 75.5°, August tied with 2001 and 1955 as the 6th warmest. This is 2.5° above the 1981–2010 mean. Eleven of the warmest 17 Augusts have occurred since 2001. The mean maximum of 84.8° tied for 19th warmest at 1.5° above normal, while the mean minimum of 66.1° was 3.4° above normal and ranked 4th warmest.

Statewide precipitation averaged 6.04”. This is 1.94” above normal and ranks as the 26th wettest August on record. Above-average totals occurred in northern (6.02”), southern (6.10”), and coastal (5.50”) climate divisions. The southern division (Mercer-Middlesex-Monmouth counties and south, except a narrow coastal division) saw a range from the driest area in Monmouth and parts of Mercer counties and a very wet area in Salem and Gloucester counties.