Monthly Summaries

As the warmth of summer transitions to the cold of winter, New Jersey weather conditions can vary markedly from week to week. Such was the case during October 2020, with abundant precipitation occurring from the remnants of two hurricanes, an episode of measurable snow in the north, several weeks of quite dry conditions, a number of comfortably warm days, and the first frost and freeze of the season for many locations. Put this all together and October proved to be milder and wetter than normal. The statewide monthly average temperature of 57.2° was 2.7° above the 1981–2010 mean. This ranks as the 18th mildest (tied with 1963 and 1931) over the 126 years extending back to 1895. Southern areas were warmer than northern ones in terms of actual temperature and departure from normal. The 58.8° average in the south was 3.2° above normal and ranked 15th warmest. The north averaged 54.4°, which was 2.0° on the plus side and ranking 27th mildest.

It took a wet final week of the month to push precipitation totals to the plus side of normal. The 5.15” statewide monthly average was 1.26” above normal and ranked as the 24th wettest on record. Somewhat like temperatures, there was north-south disparity. The south averaged 5.36”, which is 1.73” above normal and ranks 20th wettest. The north averaged 4.64”, which is 0.33” above normal and ranks 36th wettest. Dry conditions prevailed, most notably in the northwest, with coastal reaches wettest. Snow fell in the north on the 30th and will be discussed below.

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.

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.

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.

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.