Interactive Map: Long Periods Without Rain Leave State ‘Abnormally Dry’

Colleen O'Dea | June 12, 2015 | Map of the Week, Maps
Weathers stations across NJ are recording a water deficit, but recent precipitation has helped stave off drought conditions

Last week’s storms helped quench a thirsty New Jersey, but most of the state still remains drier than normal. Still, state officials see no need to declare drought conditions yet and report that reservoir levels are just slightly below average.

According to data from the National Agricultural Statistics Service, 14 of 17 weather stations it monitors had seen less rain than normal through Sunday. The largest precipitation deficit since April 1 was more than 4.6 inches in Belvidere in Warren County. Only three stations in South Jersey — Millville, Hammonton and Estell Manor — have had more rain since April 1 than average and that’s only because of the large amount of rain last week.

Through the end of May, every station in New Jersey was in deficit. Flemington was driest, more than 6 inches below normal. But last week brought a respite with heavy rains, with the largest amount the 6.2 inches reported in Newark.

“May 2015 was a warm and dry month across New Jersey,” wrote David A. Robinson, New Jersey state climatologist, in a report last week on May and the spring thus far. “As the month ended, drought concerns were looming large, though rainfall in the north during the afternoon and evening of the 31st and continuing into the first days of June resulted in at least a temporary braking of the downward slide.”

According to Robinson, data from the long-term National Weather Service Cooperative Observing stations show total rainfall during the month of May averaging just 1.08 inches in New Jersey. That was nearly three inches below the mean for the years 1981 through 2010 and ranks May as the third driest month on record since 1895. The driest was in 1903, when only 0.5 inches of rain fell on the state.

The dry conditions led the U.S. Drought Monitor to declare North Jersey in moderate drought at the end of May, but it has since upgraded the condition to “abnormally dry.”

The March rains and snow melt were slightly above normal, but April and May precipitation were both below, according to Robinson. The total 8.64 inches for spring thus far is nearly 3.7 inches below normal, making it the 21st driest on record.

“This helps explain why drought conditions were encroaching upon the Garden State toward the end of May,” Robinson wrote. “Such conditions are typically seen no more often than once every 10 years. From about Interstate 78 to the Atlantic City Expressway, abnormal dryness, or what might be called minor drought, was underway … Ground water, especially in the northwest, was very low, crops were growing slowly or not germinating, and reservoirs, while still at average levels, were beginning to fall at a pace not usually seen this early in the season, most likely due to considerable early-season lawn watering.”

This had farmers concerned about drought-like conditions, but happy with the recent rain. The amount of precipitation is one factor that affects crop health. Still, it’s a complicated formula, with the timing of the rain being “the most important” factor, said Peter Furey, executive director of the New Jersey Farm Bureau. Different crops do well in different conditions and temperatures also play a role.

Overall, according to Robinson, May was also the third-warmest in history, with the 66 degrees Fahrenheit statewide-average temperature registering 5.2 degrees above average. The warmest was in 2004, when May averaged 66.2 degrees.

The state Department of Environmental Protection has not issued any drought warning, which could lead to calls for water conservation measures such as restrictions on washing cars and watering lawns, that would affect New Jersey as a whole. According to DEP data, the combined reservoir-storage levels are above 90 percent, just slightly below the 1962-to-2010 average. The United and Newark reservoirs are at or slightly above normal, while those of Jersey City and the North Jersey District Water Supply Commission are slightly below.

Whether healthy levels hold, though, will be up to future weather patterns. Said Robinson, “Whether the rains of late May and early June will signify the end of dry conditions or only provide a brief and welcome respite from an increasingly worrisome situation remains to be seen.”