The National Weather Service has made it official: the summer of 2010 was the hottest ever recorded in New York City.

September has also started out warmer than usual in the five boroughs.The temperature averaged 77.8 degrees Fahrenheit from June through August, breaking the previous average high of 77.3 degrees set in 1996.

Con Edison estimated that 6.6 million air conditioners are in use in its service area, which includes New York City and Westchester County, according to the New York Times. That number has been rising by about 170,000 yearly.  Not surprisingly, then, the utility reported that 14 of its 36 distribution networks, all serving residential areas, exceeded its forecast for peak demand this summer.

The pending culmination of an 11-year solar cycle may be partly to blame for the extreme heat. Stanford University scientists reported recently they anticipate the worst heat waves in the United States today will become commonplace by the 2030s as a consequence of global  warming.

Even Bjorn Lomborg, the Danish author of "The Skeptical Environmentalist," has defected from the dwindling but often noisy ranks of those who don't consider climate change a problem. Just in time for Halloween, his new book, "Smart Solutions to Climate Change: Comparing Costs and Benefits," is set for release, Yahoo News reported.