Anomalous Warmth Continues
May 2012, Spring 2012, and Snow Season 2011/12 Summaries

Dr. David A. Robinson
New Jersey State Climatologist
Center for Environmental Prediction, School of Environmental and Biological Sciences/NJAES, Rutgers University
June 4, 2012

May Overview

There were two major story lines to May weather conditions. First was the warmth, bringing New Jersey its 16th consecutive month of above-average temperatures (and 24 of the past 27 months too). The warmest weather occurred over the Memorial Day weekend, making it feel more like the 4th of July than late May. Second was the near-average rainfall, the first month of 2012 without sub-average totals. Still, the extreme southern portion of the state is in the early stages of drought. Elsewhere, there have been noticeable improvements in all aspects of the water budget, however year-to-date precipitation totals remain multiple inches below average and in some locations ground water and stream flows have yet to get up to average for this time of the year. Reservoirs are in good shape and the vast majority of NJ is in far better hydrologic shape than it was before the April 22nd nor'easter marked the onset of a return to more average conditions.

May temperatures across NJ averaged 65.0°, which is 4.2° above average. This ranks as the 4th warmest May since records commenced in 1895 (Table 1). Statewide temperatures in ten of the past fourteen months have fallen in the top ten warmest of their respective month, a remarkable total when you consider observations go back 117 years (118 for Jan.-May). The first five months of 2012 also comprised the warmest of all such Jan.-May periods on record.

Rank Year May Avg. Temp.
1 2004 66.2°
2 1991 66.1°
2 1944 66.1°
4 2012 65.0°
5 1896 64.9°
6 1965 64.4°
7 2010 64.2°
8 1911 64.1°
8 1918 64.1°
10 1942 64.0°
10 2011 64.0°

Table 1. The eleven warmest Mays across NJ since 1895.

Temperatures were rather consistently mild throughout May, with about three quarters of the days averaging above normal. Daily minimum temperatures led the way, with maximums not as abnormally high. This was due to frequent cloud cover and showers. The thermometer equaled or exceeded 85° somewhere in the state on six afternoons, all within the last week of the month. Sicklerville (Camden County) and Piney Hollow (Gloucester) reached 85° on the 25th. Haworth (Bergen) got to 89° on the 26th, when three other stations reached 88°. Sicklerville and Piney Hollow again took top honors on the 27th at 88° with seven stations at 87°. The first 90° readings since April 16th arrived on the 28th with Hawthorne (Passaic) and Oswego Lake (Burlington) at 94°. This Memorial Day heat saw another 21 of the 45 stations monitored daily by the State Climate Office warming to between 90° and 93°. The lowest maximum was 78° in Bivalve (Cumberland). The 29th was just a bit hotter, with Hawthorne up to 95° and 28 stations between 90° and 93°. Atlantic City Marina (Atlantic) and Harvey Cedars (Ocean) were the coolest locations at 77°. The 31st saw Berkeley Township (Ocean) top out at 85°.

Six mornings, all in the first three weeks of the month, had low temperatures in the 30°s at two or more locations. The southern half of NJ was coolest on the 7th with Cape May Courthouse (Cape May) and Berkeley Township down to 39°. The 10th saw the northwest valley locations of Walpack (Sussex) and Pequest (Warren) at 38°. Pequest fell to 32° on the 11th, with Walpack at 33°. This coldest May morning saw eight stations between 36° and 39°, with West Cape May (Cape May) considerably milder at 56°. Walpack was again at 33° on the 12th, Pequest at 34° and seven stations between 36° and 39°. West Cape May was again mildest at 53°. Walpack and Berkeley Township fell to 35° on the 18th and Walpack, Pequest, and Basking Ridge (Somerset) reached 39° on the 19th. The mildest morning of the month was on the 29th, when thirteen stations were no cooler than 70°-73°, with High Point and High Point Monument in Sussex County coolest at 62°.

Averaging the widely-ranging precipitation totals across NJ during May resulted in an average that cannot be much closer to the 1981-2010 average. The 3.95" that fell was 0.05" below average and was the 43rd wettest of the past 118 years (remembering that monthly precipitation is not statistically normally distributed, with there always being more months below the average than above it). The Warren/western Morris county area was wettest, with Rockaway (Morris) receiving 7.81" and two locations in Liberty Township (Warren) coming in with 7.23" and 6.62". A localized event in central Burlington County on the 24th helped make Southampton Township the 4th wettest location in May at 6.53". On the low end, the Cape May County locations of Middle Township (1.65"), Stone Harbor (1.94"), and Wildwood Crest (2.04") saw the least rain, along with Pitman (Gloucester; 2.04"). Rain fell on at least half of the days of the month in many locations, with some communities receiving measureable rain (0.01" or more) on as many as 21 or 22 days. While localized flash flooding occurred with some of the heavier downpours, there were no reports of significant flood, wind, or lightning damage from the thunderstorms that plagued NJ on many occasions.

The month started with a bang, as early morning thunderstorms on the 1st dumped 1.50" in Ewing (Mercer) and 1.32" at Belmar (Monmouth). Most of the northern two thirds of the state saw at least 0.25". Intervals of rain with some embedded thunderstorms from the 2nd-4th totaled 1.75" in Flemington (Hunterdon) and 1.51" at Paterson (Passaic). Most of northern half of NJ saw about 0.50", tapering down to under 0.10" in Cape May County. Another period of off and on rain from late on the 8th into the morning of the 10th saw the entire state receive 0.50" or more, with the heaviest rain along the coast from Monmouth south to Atlantic counties. Lacey Township (Ocean) was soaked with 2.74", with two Berkeley Township stations coming in with 2.60" and 2.56".

The middle of the month saw "top 10" days of clear skies, mild temperatures, and low humidity on the 12th, 13th, and 17th-19th. However in the midst of this interval an episode of on-and-off rain from the last half of the 14th to the morning of the 16th brought west-central areas over an inch with at least 0.25" having accumulated elsewhere. Liberty Township (Warren) took top honors with 2.49", with Somerville (Somerset) and White Township (Warren) receiving 1.89" in thunderstorms.

The 21st-22nd brought heavy rain to the Monmouth County communities of Ocean Township (2.60"), Eatontown (2.40"), and Asbury Park (2.35"). One inch plus rains extended northward into Bergen County, with the least in the northwest and far south. Showers and thunderstorms returned to the northern half and parts of the southwest of NJ on the 23rd, with 3.04" at Pequest (Warren), 2.32" in East Greenwich (Gloucester), 2.25" in Liberty Township (Warren), and 1.99" at Medford (Burlington). The aforementioned localized storm brought 2.35" to Southampton Township (Burlington) on the 24th, with nearby Chesterfield (Burlington) catching 1.39". Rain from late on the 26th to the morning of the 27th brought 1.11" to both Woodland Township (Burlington) and Bethlehem Township (Hunterdon). Scattered areas in other areas of NJ received 0.50" or more, with no rain falling in the extreme south. The evening of the 29th through the morning of the 30th saw scattered areas in the northern half and in the south from Salem to Cape May counties receive 0.50" or more. Upper Township (Cape May) caught 1.24" and Sussex (Sussex) 1.18".

May was not a particularly windy month, with only three days seeing gusts at or exceeding 40 mph at one or more location. The 10th was the windiest with High Point Monument (Sussex) gusts reaching 44 mph and eight stations up to 30-36 mph. The Monument reached 40 mph on the 11th, with two stations between 30-37 mph. High Point Monument and Wantage (Sussex) gusted to 43 mph on the 29th, when six stations were from 30-35 mph. Linked with the lower winds of this May were rather minor day-to-day pressure gradients. The lowest pressures were on the 10th, at between 29.45"-29.50", with the highest on the 12th between 30.25"-30.30".

Spring Overview

Spring 2012 (March-May) goes into the record book as the warmest on record for the Garden State (Table 2). The average temperature of 55.8° was 4.7° above average. This follows the 3rd hottest summer, 3rd warmest fall, and 4th mildest winter.

Rank Year Spring Avg. Temp.
1 2012 55.8°
2 2010 55.3°
3 1921 54.7°
4 1991 54.0°
5 1945 53.9°
6 1977 53.7°
6 2004 53.7°
8 1998 53.5°
9 1903 53.2°
10 1985 53.1°
10 2011 53.1°

Table 2. The eleven warmest March-May intervals across New Jersey since 1895.

It is interesting that amidst this warmth the interval of time between the first and last freeze of the cold season was close to average in most locations. This was the result of a late first freeze on October 28th in most places (a day before the snow storm) and a late last freeze for most locations on one of the last three mornings of April (October 28th-April 30th is 186 days). Each was about two weeks later than average. The longest interval of freezing weather was at Pequest (Warren) with an October 28th first freeze and May 11th last freeze (197 days). The shortest freeze season was at Atlantic City Marina (Atlantic) with a first freeze on December 11th and last on March 10th, making for only a 91 day season. A few other coastal locations had short seasons too, namely Harvey Cedars (Ocean) and Seaside Heights (Ocean), both 108 days from December 11th-March 27th. West Cape May (Cape May) had a 133 day season starting on October 31st and ending early on March 11th. Newark Airport, representing urban areas, had a first freeze on October 31st and last on March 27th, spanning 149 days.

Spring precipitation averaged 8.86" across NJ. This is 3.43" below average and ranks as the 24th driest on record. The wettest locations were in the Highlands, with 12.52" at Rockaway (Morris) and along the northern coast where Ocean Township (Monmouth) received 11.93" and Asbury Park (Monmouth) 11.77". Southern locations were driest, with only 5.82" in Middle Township (Cape May), 6.77" at Wildwood Crest (Cape May), 7.28" in Woolwich Township (Gloucester), and 7.44" in Woodstown (Salem).

Snow Season Recap

For snow lovers, there wasn't any better way to start the snow season in northern and central NJ than the October 29th storm. This brought record-breaking early season snow, totaling as much as 19.1" at Barry Lakes (Sussex). While much lower amounts fell at lower elevations, roads needed plowing and many leaf- and snow-laden trees came down on power lines, automobiles, and homes. Little did we know that this would be the largest storm of the 2011/2012 snow season, making the season one of the lowest ranking on record. At individual stations, the highest totals were not surprisingly in those locations hit hardest in October. Barry Lakes received 31.0" for the season, with Mine Hill (Morris) at 23.8" and Rockaway Township (Morris) with 23.6". On the low end, the Cape May County communities of Woodbine and Upper Township measured only 0.5" for the season, with Middle Township (Cape May) at 0.9".

Recently, the State Climate Office generated regional monthly and seasonal snow totals back to the winter of 1894/1895. Our Northern region includes the counties of Sussex, Warren, Morris, Passaic, Bergen, Hudson and Essex. The Central region has Hunterdon, Somerset, Mercer, Middlesex, Union and Monmouth. Burlington, Ocean, Camden, Gloucester, Salem, Cumberland, Atlantic and Cape May encompass the Southern region. Table 3 includes the 2011/2012 seasonal and monthly totals for each region and the state as a whole, this past season's ranking (of the past 118 seasons), and the period of record seasonal average (no measureable snow fell in April). The North had the most snow but ranked lowest due to its normally higher average, while the South had the least snow but only ranked 9th lowest.

For comparison, annual snowfall statewide has ranged from 3.9" in 1972/73 to 62.8" in 1995/96. The North has ranged from 6.6" in 1918/19 to 84.5" in 1995/96, Central from 3.4" in 1918/19 to 68.4" in 1995/96, and South 0.9" in 1972/73 to 66.5" in 2009/10.

Had the October snowstorm not occurred, the South ranking would have remained the same, while the Central would have fallen to 4th, the North to least snowy, and the state to 3rd least snowy season.

Total 2011/12 Rank 2011/12 Long-term Average Oct. Nov. Dec. Jan. Feb. Mar.
NJ 7.4" 6 26.1" 2.8" 0.0" 0.0" 2.7" 1.8" 0.1"
North 12.1" 5 34.7" 6.7" 0.0" 0.1" 4.1" 1.0" 0.2"
Central 9.1" 7 28.9" 4.0" 0.0" 0.0" 3.0" 2.1" 0.0"
South 4.0" 9 19.9" 0.1" 0.0" 0.0" 1.8" 2.1" 0.0"

Table 3. Seasonal and monthly snowfall totals and rankings (from lowest) for New Jersey and three regions.

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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Past Climate Summaries