Monthly Summaries

Summer Arrives: June Recap (with a brief look at the first half of 2020)

July 7, 2020 - 4:44pm -- Dave Robinson

Tree blown over from June 3rd derecho

The statewide average precipitation this June was 3.10”. This is 0.91” below the 1981–2010 average and ranks as the 43rd driest of the past 126 Junes. As is typical during the warm season, where the bulk of the rainfall is provided by showers and thunderstorms, totals varied widely from location to location, even at times in close proximity to one another. Monmouth and northern Ocean counties saw the most, totaling over 5.00” in spots, with a secondary maximum in Gloucester County. The Highlands, portions of central NJ, and southern Ocean and Cape May counties saw as little as 1.00–2.00”.

The statewide average temperature of 71.6° was 1.8° above the 1981–2010 normal. This ranks as the 10th warmest, joining four other years this century in the top 10, while being the warmest since 2011.

Endless Spring: May and Spring 2020 Recaps

June 7, 2020 - 6:34pm -- Dave Robinson

In recent years, many a comment has been heard that New Jersey just does not have a spring season any more. We go right from winter to summer weather, people say. The same cannot be said for spring 2020. A seasonal summary follows at the end of this report and the individual March and April reports can be found on the state climate office website. To begin here, the talk will be of May, a month that produced both less rain and cooler temperatures than normal and included an unusual appearance of snow.

The statewide average temperature of 58.9° was 1.7° below the 1981–2010 normal. This ranked as the 40th coolest May since records commenced in 1895. April and May marked the first time since December 2017–January 2018 that consecutive months had below-average temperatures. Statewide, May precipitation averaged 2.50”. This was 1.49” below normal and ranked as the 29th driest on record.

Blown Away: April 2020 Recap

May 5, 2020 - 10:23pm -- Dave Robinson

Gas station canopy collapse

If you have a sense that April was unusually windy, you are certainly not alone. While long-term wind observations are few across the Garden State and those available suffer from inconsistencies in instrumentation and location, seat-of-the-pants judgment tells us that plenty of air raced crossed the state throughout the month. In fact, the wind gusted to 40 mph or higher at one or more NJWxNet station on 12 days. Of those, seven had gusts from 50–59 mph and an impressive four gusted over 60 mph. The highest network gust of 76 mph occurred at Sea Girt (Monmouth County) on the 21st. There were also reports from other seemingly reliable stations of gusts as high as 82 mph at Island Beach State Park (Ocean) on the 13th.

April precipitation achieved a statewide average of 3.92”. This is 0.07” below the 1981–2010 mean, but given the skewness of the distribution of April rainfall over the past 126 years, it ranks as the 45th wettest. Despite Morris County stations having the highest monthly totals, overall, the north part of the state was driest. The mean of 3.66” was 0.54” below normal and is the 59th driest (68th wettest). The south averaged 4.07”, which is 0.21” above normal and is 40th wettest. The narrow coastal region averaged 4.16”, which is 0.33” above normal and ranks 39th wettest.

Spring Ahead: March 2020 Recap

April 7, 2020 - 11:40am -- Dave Robinson

March 2020 was the 6th mildest in New Jersey dating back to 1895. Combined with mild rankings of 9th in January and 4th in February, 2020 has started off as the 2nd mildest on record at 5.8° above the 1981–2010 average. The 40.8° average only falls behind 2012’s 41.4°. Six of the ten mildest January–March intervals in the past 126 years have occurred since 2002.

March averaged 46.3° across NJ, which is 5.5° above average. The average maximum of 56.2° (+5.4°) ranked 7th mildest and the minimum of 36.4° (+5.6°) 2nd mildest. Anomalies were +5.8° in both the southern (47.9°) and coastal (47.7°) divisions, ranking 6th and 4th mildest, respectively, and +5.0° in the north (43.7°), ranking 9th mildest. As a result of the premature warmth, vegetation green up across the state was at least two weeks earlier than normal.

More Like Virginia: February 2020 and Winter 2019/20 Recaps

March 3, 2020 - 10:57pm -- Dave Robinson

Controlled burn smoke photo

Following on the heels of the 8th mildest January on record, February 2020 entered the books as the 3rd mildest since records began in 1895. The 39.2° average was 5.7° above the 1981–2010 mean. The northern climate division of the state averaged 36.2° (+5.2°; 6th mildest), the south was 41.0° (+6.1°; 3rd mildest), and the coastal division was 41.2° (+5.7°; 3rd mildest). Average minimum temperatures ranked 2nd mildest for the state, while average maximums ranked 8th mildest. To place February 2020 in some perspective, it was just 1.6° below the 1981–2010 March average of 40.8° and only 0.2° below the longer 1895–2019 March average. It was close to the long-term (1981–2010) average February temperatures in Washington, DC, Paducah, KY, and Bristol, TN.

February precipitation (rain and melted snow) came in very close to the 1981–2010 average at 2.82”. This is just 0.02” above average and ranks as the 62nd driest (and 65th wettest) of the past 126 years. Divisional totals ranged from 2.48” (-0.34”, 49th driest) in the north, 2.99” (+0.21”, 60th wettest) in the south, and 3.37” (+0.48”, 51st wettest) at the coast.

Cold and Dry (A Rarity of Late), and Quite the Transition Season: November and Fall 2019 Recaps

December 5, 2019 - 5:28pm -- Dave Robinson

Leaf bags

In what has been a monthly see-saw of an autumn in the precipitation department (more below), November totals were on the low side. The statewide average total of 1.83” was 1.78” below the 1981–2010 mean. This ranked as the 22nd driest November since 1895. The northern half of the state averaged 2.31”, which is 1.55” below normal and ranks 31st driest. The south was drier at 1.54”, which is 1.91” below normal and ties with 1991 as the 18th driest. Temperature-wise it was the coldest month compared to normal since last November and, along with March, only the second below average one since then. The statewide average temperature of 41.3° was 3.9° below normal and ranks as the 27th coldest (tied with 1920 and 1955) of the past 125 Novembers. The north average 38.9°, which is 4.2° below normal and ties with six other years as the 24th coolest. The south averaged 42.6°, which is 3.8° below normal and ties with 1954 and 1972 as 27th coolest. Of late, there have been warmer and drier months compared to the norm, such as this past September and colder and wetter months including this past March. However, the last time New Jersey experienced a noteworthy dry and cold month (of any month) was November 2012 when the statewide average temperature was 3.7° below average and the precipitation 2.31” below average.

So Much for a Flash Drought: October 2019 Recap

November 6, 2019 - 2:33pm -- Dave Robinson

As the 10th month of 2019 commenced, attention was on the continuing flash drought conditions across the Garden State. Lawns had gone brown and shallow rooted trees were losing their dull-colored leaves early. By the second week of the month, the US Drought Monitor showed all of NJ to be in either abnormally dry (D0) or moderate drought (D1) status (full disclosure: my recommendations are taken under consideration by the national author of each week’s map). Several rain episodes in the first half of the month, particularly in the north, began to stall any worsening of conditions. However, it wasn’t until the last half that five events deposited an inch or more, three of them with two inches or more, at a number of locations around the state. Thus by month’s end, only portions of southwest, southeast, and central NJ were rated D0, and the remainder, as we like to say, in “D nada.” This turn to storminess didn’t come without consequences. This included localized flash and small stream flooding on occasion, several episodes of strong winds, and some minor to moderate coastal flooding. More on all of this below, but first to further summarize the month. In the precipitation department, the statewide average was 5.79”. This is 1.90” above the 1981–2010 normal and ranks as the 15th wettest dating back to 1895. North Jersey came in with an average of 6.72”, some 2.41” above normal and ranking 10th wettest. In the south, the 5.28” average was 1.65” above normal and ranks as the 20th wettest.

As if the wet month was not newsworthy enough, the statewide monthly temperature of 58.0° tied with two other years as the 9th warmest back to 1895. This is 3.5° above normal, with northern and southern portions coming in at 3.2° and 3.8° above, respectively. The 2nd was arguably the hottest October day on record, thus also the warmest for so late in the season. Meanwhile, several locations experienced the first freeze of the season on the 4th or 5th, with a more widespread frost and freeze on the 19th. Still, the month ended with only 18 of the 63 NJWxNet stations having fallen to the freezing mark.

Off Goes the Faucet: September 2019 Recap

October 7, 2019 - 5:26pm -- Mathieu Gerbush

Drought photo

No months prior to this past September have been drier across New Jersey since February 2009, a testament to how precipitation has leaned toward the wet side since the last major drought impacted the state in 2002. The 1.21” received this September was 2.84” below the 1981–2010 average. This ranked as the 7th driest September since records commenced in 1895. February 2009 saw only 0.66”, but since February is on average the driest month of the year (2.80”), the last time a monthly deficit was larger than this September was the 3.06” departure in September 2007. Since 2000, only six other months early in the century have been drier (February 2002: 0.75”, October 2000: 0.77”, March 2006: 0.82”, October 2001: 0.93”, November 2001: 1.00”, and September 2005: 1.19”).

Conditions were driest in the north, averaging 1.06”, which is 3.41” below normal and ranks as the 4th driest September on record. Southern NJ ranked 12th driest with 1.30”, which is 2.52” below normal. This “flash drought” depleted soil moisture, resulting in brown lawns and shallow-rooted trees losing leaves early. Fire danger also increased, resulting in a ban on open fires. At month’s end, the US Drought Monitor had most of NJ in the D0 (abnormally dry) category, with Salem County experiencing moderate drought (D1) conditions. Thanks to above-average precipitation earlier this year, northern NJ reservoir levels remained above early-fall averages. Certainly, a watchful eye will be kept on all water resources should this dry spell continue.

Above-average temperatures helped to dry things out in September. The 69.1° statewide average was 3.3° above the 1981–2010 mean. This ranks as the 8th warmest September over the past 125 years (tied with 1921; Table 2). Southern areas were warmest, at 3.5° above normal, while the north was 2.8° above.

Leaning Warm and a Bit Dry, and Once Again, Top-Ten Warmth: August and Summer 2019 Recaps

September 6, 2019 - 2:03pm -- Dave Robinson

Flash flood photo

The summer of 2019 concluded on a warm and a bit dry note when averaged across the Garden State. The warmth was a common theme throughout June to August, while the earlier summer months were on the wet side. The average August temperature of 74.4° was 1.4° above the 1981–2010 mean and is tied with 1983 and 1973 as the 14th warmest since 1895. On 12 days, the temperature topped out at 90° or hotter at one or more Rutgers NJ Weather Network station, but never exceeded 96°. The heat was somewhat tempered by seven mornings with lows in the 40°s at some northwestern NJWxNet locations.

August precipitation averaged 3.75” across NJ. This was 0.35” below normal and ranks as the 52nd driest of the past 125 Augusts. As expected during a summer month that is dominated by hit and miss showers, rainfall totals varied quite a bit, even on a local scale. The driest location in the state was Lambertville in Hunterdon County where 1.48” fell, while the wettest was Lebanon, also in Hunterdon County, with 7.99”. When and where the storms struck, they were, at times, intense. This included small tornadoes and more widespread strong winds, dangerous lightning, and flash flooding.

Mother Nature Picking on Two NJ Communities!: July 2019 Recap

August 4, 2019 - 2:30pm -- Dave Robinson

Thunderstorm wind damage in Holmdel

With 565 incorporated communities in New Jersey, one would think that the odds of multiple significant weather events specific to any one of them within a month would be exceedingly rare. Yet July 2019 brought such a duel scenario to not one but two NJ townships. Mt. Laurel (Burlington County) was visited by two tornadoes, while one rain gauge in Stafford Township (Ocean) caught 5.00” in two separate 24 hour periods. More specifics are provided later in this report. The good news is that, despite damage occurring in each of the four events, there were no fatalities nor reported injuries.

The month as a whole was a wet one, averaging 6.15” across the state. This is 1.58” above the 1981–2010 mean and ranks as the 20th wettest since 1895. Northern counties were wettest, averaging 7.20” or some 2.45” above normal and ranking 16th wettest. The south averaged 5.61”, which is 1.12” above normal and ranks 29th wettest.

Ten of the past 12 months and 15 of the past 18 months have received above-average precipitation across the state. While the 12 months ending in January this year ranks as wettest (66.61”) of 1484 such intervals dating back to 1895, the past 12 month period ending in July comes in second place with 65.74”, just ahead of the 12 months ending in June (65.50”).


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