A Warm and Dry May
May 2007 Climate Summary

Dr. David A. Robinson
New Jersey State Climatologist
Center for Environmental Prediction, Cook College/NJAES, Rutgers University
June 3, 2007

The record wet conditions of April were only a memory this past May. Dry weather enveloped the Garden State, where, on average, only 1.55" of precipitation fell. This totals some 2.75" below the 4.30" average. May 2007 went into the record books as the 11th driest since 1895, and the most parched since 1993. The driest was in 1903, when the state wide average was 0.53". Early in the month surface conditions quickly dried, to the point where 17,000 acres of the Pinelands went up in flames, primarily on the 15th and 16th (click here for MODIS satellite image from 2:25 PM on May 16 of smoke from the Pinelands fire, courtesy of NASA). Ground water levels and the discharge of rivers continued to diminish throughout the month, while the rains of April helped to keep the capacities of our reservoirs close to average as we enter the three warmest and most water consumptive months of the year.

Warm temperatures accompanied the dry conditions. The statewide May temperature averaged 62.9°, which is 2.3° above the long term 60.6°. This was the 15th warmest May on record, and the mildest since 2004 (which was the warmest of the past 113). Temperatures were above average on 20 days, average on one and below average on 10 (as observed at both Newark and Atlantic City airports). The dry conditions helped contribute to some large swings in temperature. For instance, at one or more locations temperatures fell below freezing on 7 mornings during the month, while afternoon maximums topped out at 90 or above on 4 other days. The coldest morning readings were in the northwest valleys and in the sandy Pinelands, while the warmest afternoons were in the piedmont and inner coastal plain. On the 30th, the Walpack SafetyNet station rose from a morning low of 39° to an afternoon high of 88°, by NJ standards an unusually wide 49° diurnal temperature range.

It wouldn't be May in New Jersey without the thermal impact of the still cool ocean on local temperature. For instance, while afternoon temperatures reached 80 or above at High Point on 7 days, Harvey Cedars on Long Beach Island reached 80 for the first time on the 31st.

Looking ahead toward the summer months, the National Weather Service's June-August outlook has a slight chance of temperatures leaning toward the warmer than normal side, with equal chances of rainfall being above, close to or below normal. Looking ahead to the July-September outlook, they keep the warmth and increase the probability of precipitation running above average. The latter may be the result of the National Hurricane Center's outlook for an active tropical season. However it must be emphasized that skillful long range outlooks are difficult to make for New Jersey, especially during the summer. Also, the Hurricane Center does not project where storms may head. Thus while it is important that everyone living or vacationing in NJ must make a point to be hurricane aware, there are no predictions for tropical systems to directly strike the state this coming summer.

Past Climate Summaries