A Record Warm June-July: July 2008 Summary and Summer Update

Dr. David A. Robinson
New Jersey State Climatologist
Center for Environmental Prediction, School of Environmental and Biological Sciences/NJAES, Rutgers University
August 2, 2008

On the heels of the 4th warmest June on record (back to 1895), New Jersey experienced its 9th warmest July. Averaged together, the first two months of this summer ranked as the warmest such period on record.

A preliminary assessment of July temperatures found a statewide average temperature of 76.7°. The anomaly of 2.2° tied for 9th warmest with two other years (table below). At least one location in the state had a maximum temperature of 90° or greater on 17 days. The 17th to 20th of the month saw a number of areas top out in the upper 90s, and surrounding this period, some stations equaled or exceeded 90° on 11 of 12 consecutive days.

Rank Year July Avg. Temp
1 1955 79.0°
2 1999 78.4°
3 1949 77.8°
4 2006 77.3°
5 1994 77.1°
6 1901 77.0°
7 1993 76.9°
8 1952 76.8°
9 2008 76.7°
9 1988 76.7°
9 2005 76.7°

Once the full array of station observations have arrived at the National Climatic Data Center and are run through a quality assessment, it is possible that the 2008 values for the past two months may change by a tenth of a degree or two. However for now, 2008 reigns as the warmest beginning to middle of summer (table below). Note that 5 of the top 10 such periods have occurred since 1994. It would take the second warmest August on record to propel this summer to the top spot that is currently held by 2005. Conversely, August temperatures will have to average 71.4° (-1.4°) or lower to keep this summer from finishing in the top 10 for warmth.

Rank Year June+July Avg. Temp
1 2008 75.0°
2 1994 74.9°
3 1949 74.8°
4 2005 74.7°
5 1999 74.6°
6 1952 74.3°
7 1943 74.1°
8 1934 74.0°
9 2006 74.0°
10 1987 73.7°

While air conditioners hummed and electric bills soared in July, so too were water bills on the high side for those seeking to keep their lawns green and gardens growing. NJ flirted with excessively dry conditions in July, just as was the case in June. The above average temperatures only exacerbated the situation by drying things out quickly whenever rain happened to fall. Fortunately, reservoirs were quite full going into the summer and rainfall has been timely enough to keep drought worries somewhat at bay. Preliminary numbers show July precipitation averaging 3.35" statewide, which is 1.14" below average and the 31st driest of the past 114.

Measureable (0.01" or more) rain fell at one place or another on 19 days during July, but as is often the case during the summer, on many days the distribution of showers and thunderstorms was quite spotty. The wettest event of the month centered on west central NJ from the morning of the 23rd through midday on the 24th. Lawrence Township (Mercer County) with 3.94" and Hillsborough Township (Somerset County) with 3.85" were the big winners, while several shore communities failed to receive any rain during these two days.

Of the 51 NJ CoCoRaHS stations that reported on 30 or 31 days, monthly totals ranged from 2.04" in Bridgeton (Cumberland County) and 2.60" in Lake Como (Monmouth County) to 6.34" in Lawrence Township and 6.08" in Moorestown (Burlington County).

Combined rainfall for June and July averaged 6.56" across the state. This ranks as the 23rd driest such interval, some 1.72" or approximately 20% below average. Ample August rains would be most welcome.

Past Climate Summaries

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