Monthly Summaries

“Holding On.” Perhaps you’re a bit perplexed attempting to interpret the title of this month’s report. Something with respect to temperature? Certainly, the warm season hardly relinquished its grip on the Garden State during the past month. September temperatures averaged above normal, mainly due to the second half of the month being warmer than the first half. Normally the second half averages approximately 5.0°–5.5° cooler than the first, however this year’s second half was 1.0°–1.5° milder than the first half in the north and about 2° milder in the south. Something regarding precipitation? It was the second consecutive month with below-normal statewide precipitation, with eleven of the past thirteen months having below-normal precipitation. The month ended with most of north Jersey categorized on the US Drought Monitor as being Abnormally Dry or in Moderate Drought, and October 1st found the NJ Department of Environmental Protection declaring a Drought Watch across the entire state. Despite this, the state has not slid into a significant drought situation as is currently found in New England. Water resources are holding on but certainly are more vulnerable than anyone would like.

Statewide, the September temperature averaged 68.1°. This was 1.2° above the 1991–2020 normal and ranked as the 16th warmest September since records commenced in 1895. Ten of the twenty warmest Septembers have occurred since 2010. The average high was 78.0°, which is 0.8° above normal and ranks as the 26th warmest on record. The average low was 58.2°, which is 1.6° above normal and ranks as 12th warmest. The northern climate division averaged 66.9° (+2.0°, 8th warmest), the southern division 68.8° (+0.7°, 25th warmest), and the coastal division 69.0° (+0.3°, 28th warmest).

Tragically, this July demonstrated how weather danger lurks across the Garden State during summer months. July thunderstorm winds felled trees that resulted in three fatalities, lightning strikes killed two and injured others, and flash flooding took two lives and put countless others in perilous situations. No doubt, the often-relentless heat and humidity led to medical issues for those most vulnerable, be they old, young, infirmed, employed outdoors, or living in stifling locations devoid of air conditioning.

Temperature-wise, the July statewide average temperature of 78.1° was 2.7° above the 1991–2020 mean and ranked as the 6th warmest since records commenced in 1895. The average high of 87.7° was 2.0° above normal, ranking 12th warmest, while the average low of 68.5° was 3.4° above normal, ranking 3rd warmest. Eight of the ten warmest Julys have occurred since 2010 and twelve of fifteen since 1999. Only three Julys in the past 25 years have averaged below the 1991–2010 normal. The June–July average of 75.0° is the 5th warmest, only exceeded by 76.1° in 2010, 75.6° in 2024, and 75.2° in both 2020 and 2011.

The 5.44” statewide average July precipitation was 0.73” above normal, ranking 42nd wettest of the past 131 Julys. As is often seen during summer months, totals varied markedly over rather short distances, seen this month in both the north and south. Overall, the north averaged 4.62” (-0.10”, 64th wettest/68th driest), south 5.93” (+1.19”, 26th wettest), and coast 6.08” (+1.70”, 20th wettest).

It took a frustratingly long time for the cool season “recharge” of New Jersey’s water resources to get well underway. Following a record dry fall 2024, December through April precipitation remained below normal, including the third driest January of the past 131 years. However, February, March, and April precipitation totals were only a bit below normal, so while precipitation deficits were not recovering, they did not worsen, and reservoirs began to fill. Then along came May, with near record-high precipitation, just in time to bring most water resources up to normal heading into summer. Yes, quite a relief! The only cautionary note regards groundwater deficits that remain at some locations in the sandy substrate of south Jersey. This impacts local streamflow as well once runoff from any recent rains has diminished, leaving the streams fed by depleted spring waters. Thus, the NJ Department of Environmental Protection has not lifted the drought warning that was established in mid-November 2024.

As for May, the statewide average precipitation was 7.27”. This was 3.52” above the 1991–2020 normal and ranks as the 5th wettest May since statewide records became established in 1895. It is the wettest May since 1990, and the fifth May this century to fall into the top 25 (three have been in the driest 25).

May temperatures exhibited some notable swings, with the end of the month’s below-normal conditions just about balancing out the above-normal start. The statewide average of 62.0° was 0.8° above normal and ranks as the 30th mildest of the past 131 years. The statewide average high temperature was 71.5°, which was 0.8° below normal and ranked as the 65th warmest/66th coolest on record. Meanwhile, the 52.5° average low was 2.3° above normal, ranking as the 12th mildest. This sign disparity is the result of the frequent cloudy and wet conditions that suppressed both daytime warmth and nighttime cooling.

Some Marches in past years have kept you guessing when, sometimes even if, spring will arrive. That certainly was not the case this year, nor, for that matter, has it been much so in recent years. With a statewide ranking of tenth warmest, March 2025 was the fourth of the past ten years to rank in the top ten. Eight of the sixteen mildest Marches in the past 131 years have occurred since 2000. Not even a late-season snow event occurred to temporarily stifle spring fever, as no measurable snow was observed anywhere in the state. Spring showers arrived and were plentiful enough to approach the statewide monthly normal. However, March finished as the seventh consecutive and tenth of the past eleven months with below-normal precipitation. As a result, there were multiple wildfires, rather common in NJ springs.

Looking more closely at numbers, the statewide March average temperature of 45.7° was 4.7° above the 1991–2020 normal and, as mentioned previously, ranked as the tenth mildest since records commenced in 1895. The average high was 57.2°, which is 6.3° above normal and ranks sixth mildest. The average low was closer to normal at 34.1°, which is 2.9° above normal and ranks thirteenth mildest (tied with three other years). The northern climate division averaged 43.6° (+4.8°, 11th mildest), the southern division 47.0° (+4.6°, 10th mildest), and the coastal division 46.4° (+4.2°, 9th mildest).

The first month of 2025 was cold, dry, and windy. It was the coldest January since 2014, one of the driest of the past 131 years, dew points dropped below zero or into the single digits on 23 days, and winds gusted to 40 mph or higher on 16 days. No doubt, a profitable outcome for those in the lip balm business!

Statewide, precipitation (rain and melted snow) averaged 0.89”. This was 2.60” below the 1991–2020 normal and ranked as the 3rd driest since records commenced in 1895. Quite a difference from last year, when January 2024 came in with 6.20”, the 7th greatest total on record. While quite meager, the northern and southeastern areas received the most precipitation, with the northern coast and southwest catching the least. The northern climate division reported 0.81” (-2.69”, 4th driest), the southern division 0.99” (-2.48”, 3rd driest), and the coastal division 0.98” (-2.53”, 3rd driest).

The statewide average monthly temperature of 28.3° was 3.4° below normal, ranking as the 45th coldest of the past 131 years. The average high of 36.4° was 3.9° below normal and ranks 44th coldest. The average low of 20.1° was 3.1° below normal and ranks 50th coldest. The northern division averaged 26.0° (-2.9°, 53rd coldest), the southern division 29.6° (-3.8°, 42nd coldest), and the coastal division 30.7° (-3.7°, 44th coldest).