NYC Temperatures to Pass 70 for First Time in 6 Months

New York City temperatures are expected to rise above 70 degrees this week for the first time since October as a cooler-than-normal weather pattern breaks, starting the transition to springlike temperatures.

New York’s Central Park may reach 78 degrees Fahrenheit (26 Celsius) tomorrow, 19 above normal, and 76 the next day, while Philadelphia may see temperatures as much as 20 degrees above normal, according to AccuWeather Inc. Boston is forecast to have a high of 68.

April is the start of a transition to warmer weather, when more energy is used to cool, rather than heat homes. Last year’s spring was the warmest on record in the U.S. Temperatures will be on the rise this week and may fluctuate thereafter, as a clash of cold and warm fronts threatens to send cooler air to the North.

“There’s going to be a battle between colder temperatures to the north and warmer temperatures to the south, which is very typical for this time of year,” Rob Carolan, founder of Hometown Forecast Services Inc. in Nashua, New Hampshire, said by phone. “The East has been cooler than normal but it looks like the pattern is breaking and warmer temperatures may be occurring on a more regular basis.”

Temperatures may reach the mid-80s in Washington by April 10. The next day, “it gets tricky and the cooler weather starts to return,” said Matt Rogers, president of Commodity Weather Group LLC in Bethesda, Maryland.

Cold Fronts

Cold fronts heading east from the Southwest and south from New England may hit the East Coast as early as April 11, bringing lower-than-normal temperatures through the weekend. Thunderstorms may also spread across the nation as a storm system emerges from the Rocky Mountains.

Temperatures in Boston may fall to as low as 36 degrees on April 12, while New York and Washington may have low of 41 degrees, AccuWeather said. Philadelphia is expected to range from 44 degrees to 63 degrees on that day.

“It’s the combination of cold fronts that will hit us -- one working down from New England, one sweeping east from the plains -- that makes the entire Northeast turn cooler,” Paul Walker, senior meteorologist at AccuWeather, said by phone from State College, Pennsylvania.

Spring Season

The national average temperature for the U.S. spring of 2012 was 57.1 degrees, 5.2 degrees above the long-term average and 2 degrees warmer than the previous mark set in 1910, according to the National Climatic Data Center.

This year’s spring has been cooler than normal and is expected to continue trending that way through the season, with fluctuations in temperatures lasting through May, Walker said.

“We’ll go back and forth where we get spells of warm weather,” he said. “Then spouts of cold weather will return.”

Following this weekend’s cooldown, warmer weather is forecast to return by the middle of next week, with the potential for 80-degree temperatures in the mid-Atlantic region.

On April 17, New York City may see a high of 67 degrees, while Washington can expect 75 and Philadelphia may reach 71.

Energy prices may be affected if humidity is high enough that people begin turning on air conditioning, Rogers said.

“The dew point should be comfortable in New York but looks like it’s going to inch up in D.C. and Philadelphia,” Rogers said. “That will add discomfort and enhance demand, at least for a day or two.”

Before it's here, it's on the Bloomberg Terminal.