December Overview

December 2011 marked the 11th consecutive month with above average temperatures across New Jersey (nineteen of the past 22 months have been above average). The average of 40.5° is 4.9° above the 1981-2010 average and ranks as the 5th warmest December since 1895 (Table 1).

While there was many a frosty morning across the state, cold air was often difficult to find, and when it arrived it didn't stay around too long. While at least one station of the close to 50-station NJ Weather and Climate Network that reports daily observations fell below freezing on 28 nights, the maximum temperature at one or more locations was 60° or higher on eleven afternoons. It took until the 11th for three coastal stations to reach the freezing point for the first time this season. That morning, Harvey Cedars (Ocean County), Atlantic City Marina (Atlantic), and Seaside Heights (Ocean) fell to 32°, 31°, and 30°. Harvey Cedars only dropped to the freezing mark on five nights in December. Meanwhile less than twenty miles to the north-northwest on the eastern edge of the Pinelands, Berkeley Township had already fallen below freezing on 40 days this season by the end of December.

Warmth was experienced throughout the month, beginning on the 4th when Piney Hollow (Gloucester) reached 60°. The 5th and 6th were the two warmest days of December. Woodbine (Cape May) reached 66° on the 5th, with 22 other stations between 60°-65° and 20 more between 57°-59°. Woodbine, Oswego Lake (Burlington), and Mullica (Atlantic) all hit 65° on the 6th, with 30 other stations between 60°-64°. The High Point and High Point Monument sites (Sussex) were the coolest locations this day at 55°. This first shot of warmth ended on the 7th with Woodbine at 65° and six stations at 62°. The 15th and 16th brought 62° maximums to Howell (Monmouth), with Mullica joining in at that mark on the 15th. Howell again was the warm spot at 64° on the 21st, shared with Bethel Mill Park (Gloucester) and Cherry Hill (Camden). Howell also reached 64° on the 22nd. The 23rd saw Woodbine top out at 62°, while High Point Monument only made it to 41°. The last week of the month saw Cherry Hill and Mansfield (Burlington) at 60° on the 27th and Woodbine and Egg Harbor (Atlantic) reach 61° on the 31st.

The coldest afternoon of the month was the 18th, with 22 stations not making it above freezing. High Point Monument had the coldest maximum at 24°, while Woodstown (Salem) and Woodbine were mildest at 38°. On thirteen December mornings the minimum dropped to the teens or lower at one or more NJ locations. The 9th saw Berkeley Township at 19°. Walpack (Sussex) took low honors from the 10th-13th at 17°, 10°, 8°, and 9°, respectively. The next coldest station on the last three of these nights was 5 degrees warmer, further solidifying Walpack's place as the coldest NJ location on many a clear, calm night.

High Point Monument was the cold spot on the 17th at 19°. The 18th and 19th brought the coldest minimums of the month, with Walpack at 8° and High Point Monument at 10° on the 17th when 26 stations were between 8°-19°. The 18th saw Walpack at 9°, Berkeley Township at 11°, and 29 stations between 9°-19°. Few stations got into the teens later in the month. Walpack fell to 15° on the 24th and 25th and to 19° on the 28th. High Point Monument dropped to 19° on the 28th and 12° on the 29th.

December 2011 precipitation across NJ averaged 4.37". This is 0.46" above the 1981-2010 average and ranks as the 34th wettest December since 1895. Two West Milford (Passaic) Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) stations took top honors with 5.65" and 5.45" received. Hardyston (Sussex) was next with 5.39" and Washington Township (Mercer) had 5.29". On the low end were the Cape May County locations of Wildwood Crest (2.14"), Lower Township (2.79"), and Middle Township (2.93").

There were only four notable precipitation events this month, with three of them producing more than an inch at one or more locations. The major episode was from the afternoon of the 6th through the pre-dawn hours of the 8th. The entire state saw a soaking rain, with only a few locations in the coastal southeast coming in with under an inch. The widespread geographic nature of the heavy rain was evident, as the eight largest totals (of almost 200 CoCoRaHS observations) occurred in eight different counties. This included Moorestown (Burlington) 3.00", Pitman (Gloucester) 2.98", Princeton (Mercer) 2.96", River Vale (Bergen) 2.94", South Brunswick (Middlesex) 2.93", Hardyston (Sussex) 2.88", Blairstown (Warren) 2.87", and Greenwich Township (Cumberland) 2.86". Wildwood Crest was driest with 0.79". Thunderstorms rumbled through portions of central and northern NJ during the late evening of the 7th. Minor flooding ensued on streams and rivers in a variety of locations but rather quickly subsided. The tail end of the storm brought the only measurable snow of December to NJ. The higher elevations of the northwest saw minor totals of 2.5" at the High Point State Park ranger station (Sussex), 1.0" in West Milford (Passaic) and Wantage (Sussex), 0.6" in Mt. Olive (Morris), and 0.3" in Liberty Township (Warren). Many locations around NJ did not see a flurry during the month.

A modest event during the PM hours of the 21st brought 0.47" and 0.55" to two Woodbine (Cape May) stations, 0.45" to Sea Isle City (Cape May), 0.45" to Wantage, and 0.42" and 0.43" to two Blairstown stations. The least amount of rain fell from Salem County northeast to Ocean County. Close on the heels of that rain came a more formidable soaking from late on the 22nd through dawn on the 23rd. This time the most rain fell from Salem County northeast to Monmouth County, and included 1.58" at Hamilton (Mercer), 1.48" in Belmar (Monmouth), and 1.47" in both Howell and Brick (Monmouth). Two Wantage stations had the least with 0.42", and reports from four Blairstown (Warren) CoCoRaHS stations ranged from 0.43" to 0.52". Reports of late evening thunderstorms were received from central and northern locations.

The final rains of a record wet 2011 fell during the PM hours of the 27th as an unseasonable squall line, replete with lightning and thunder in several central communities. Fittingly for the year, the northern third of the state saw the most rainfall and the southern third the least. Three West Milford (Passaic) stations received 1.88", 1.62", and 1.58", and Kearny (Hudson) caught 1.51". Dennis Township (Cape May) and Belmar (Monmouth) saw only 0.38".

Winds howled on a number of occasions in December, though damage reports and power outages were minimal. Gusts equaled or exceeded 40 mph at one or more NJWxNet locations on twelve days. The 1st saw a gust to 50 mph at Wantage (Sussex) and 41 mph at High Point Monument (Sussex). Wantage gusted to 46 mph on the 7th with five stations hitting 41 mph-46 mph. The 8th was one of the windiest days of month with a 50 mph gust at Seaside Heights (Ocean), 49 mph gusts at High Point Monument and Wantage, and six other stations over 40 mph. A gust of 40 mph was recorded at Atlantic City Marina on the 15th, followed by gusts on the 16th of 63 mph at High Point Monument, 56 mph at Wantage, 44 mph at Stewartsville (Warren), and 40 mph in Seaside Heights.

Parsippany (Morris) gusted to 43 mph on the 21st, with that mark reached at High Point Monument on the 23rd. The windy Monument location got up to 52 mph on the 26th, with Wantage at 40 mph. The 27th and 28th rivaled the 8th as the windiest days of the month statewide. The 27th brought a 55 mph gust to Bivalve (Cumberland), 50 mph to Atlantic City Marina and gusts into the 40's mph at six other locations. High Point Monument reached 55 mph on the 28th, with seven other stations over 40 mph. The two most frequently gusty locations in NJ ended 2011 with a 52 mph gust at High Point Monument and a 44 mph gust at Wantage on the 29th.

Highest monthly barometric pressures were observed on the 3rd and 11th when many NJ stations maxed out between 30.65"-30.70". The 27th saw the pressure plummet to 29.25"-29.30". Heavy fog was observed in many areas of the state on the 5th.

Fortunately it was another tranquil month when it came to impactful weather events. There was the aforementioned flooding from the rain storm early in the month and some fallen branches to contend with, some that were left hanging in trees following the winds of Irene and the snow of late October. Otherwise, the weather didn't interfere much with holiday traveling, including trips to shopping centers! Also, snow removal and road treatments for ice were minimal or non existent. Skaters weren't pleased, as even ponds and lakes in the northwest corner of the state were mainly ice free at month's end.

Annual 2011 Overview

To say that those of us residing in the Garden State experienced a wealth of weather and climate extremes in 2011 is an understatement. Memorable events have been chronicled in individual monthly and seasonal statements on the Office of the NJ State Climatologist website. In the following paragraphs, a synopsis of annual temperature and precipitation observations is provided, followed by the ONJSC's take on the top ten events of 2011.

Copious amounts of precipitation fell across NJ in 2011. While the remarkable rains of August and early September played a major role in making this the wettest year on record for the state, only three months had below average precipitation. The annual statewide total of 64.87" is almost 5" above the previous record and is 17.93" above the 1981-2010 average (Table 2). August was the wettest of any month on record, with 17.22" accumulating (13.01" above average). The previous monthly record of 11.98" in October 2005 was shattered. Only one consecutive 12-month interval has been wetter than this calendar year, that being the 66.60" that fell from April 2009 to March 2010. This is out of 1393 such intervals during the past 117 years! April was the 10th wettest on record, while summer was the wettest.

No portion of the state remained untouched by the heavy precipitation, with the notable exception of several locations in Cape May County where only 39.07" fell in Wildwood Crest and 40.35" at a Middle Township station. Normally the wettest area of NJ, the northern Highlands did not disappoint in 2011. While records require some additional scrutiny, it appears that the annual totals at five stations in this region exceeded the previous state record for precipitation at an individual location. As listed in Ludlum's New Jersey Weather Book, Paterson with 85.99" in 1882 had long held the record. However it is likely that a station in West Milford (Passaic) with 90.65" will assume top honors (subject to the approval of an extremes committee overseen by the National Climatic Data Center). The other top stations include another in West Milford with 86.02", Mt. Olive (Morris) at 88.15", Jefferson Township (Morris) with 87.93", and Hardyston (Sussex) at 87.84". These totals are approximately 30-35" above average! Of stations with long histories, New Brunswick (Middlesex) set an annual record of 66.13" (observations since 1893) and Newark Airport (Essex) with 69.91" also had an annual maximum (since 1931). A preliminary listing of top 2011 totals for each county is seen in Table 3. All but the Harrison, New Brunswick, Newark, Seabrook Farms, and Somerdale observations are from CoCoRaHS observers. Unfortunately, there wasn't a Union County observer with a complete enough record to generate an annual total.

The 2011 annual average temperature was close to a record breaker. The 55.2° statewide average is 2.0° above the 1981-2010 mark and 3.0° above the 1895-2010 average. It ranks as the 3rd warmest of the last 117 years, only exceeded by 1998 and 2006, and pushes 2010 back to 4th place (Table 4). Four of the top ten years for warmth have occurred in the past ten years, and eight of the ten since 1990.

The last eleven months of 2011 were above average, with seven of them ranking in the top ten for warmth in their respective month (Table 5). Spring ranked as the 9th warmest, summer 3rd and fall 3rd.

Top ten lists are always subject to debate, be it due to those events included OR excluded, along with the order of the ranking. We would love to hear your comments on the 2011 list that follows at support@climate.rutgers.edu. Remember, we were looking for events with widespread impacts. You may have experienced a severe storm at some point that was mainly localized, leaving a memory for you, but perhaps not many others. Also, when considering statewide records, they extend back to 1895.

1) Wettest year for NJ (wettest station over a calendar year)
2) Tropical Storm Irene: August 27-28 (3rd wettest rainstorm, record flooding)
3) Wettest month on record for NJ: August (wettest two consecutive months: Aug-Sep)
4) Early-season snowstorm: October 29-30
5) Third warmest year for NJ (11 months above average; seven in the top ten for their month)
6) Second hottest month on record: July (including top ten hottest day: July 22)
7) Snowstorm: January 26-27
8) Snowiest January on record for NJ
9) Back-to-back rain storms March 6-7, 10-11 (major flooding)
10) Ice storm: February 1-2

For those seeking more detailed information on hourly, daily and monthly conditions, please visit the following Office of the NJ State Climatologist's websites:

NJ Weather and Climate Network
NJ Community Collaborative Rain, Hail and Snow Network
NJ Snow Event Reports

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