Washington Early winter in the United States was pretty much missing in action this year: The past three months were the warmest November-through-January on record, according to U.S. temperature data.
The average U.S. temperature during those three months was 39.94 degrees Â a whopping 4.3 degrees more than the three-month average for the previous 106 years, according to the National Climatic Data Center in Asheville, N.C.
The old record for that period, 39.63 degrees, was set only two years ago.
November isn't technically part of winter, which begins in December, but it marked the beginning of a shift in the weather pattern that is keeping Arctic air away. More than two-thirds of the nation recorded extremely warmer-than-normal temperatures for November.
"A lot of the cold air has been bottled up in Canada," said climate center meteorologist Richard Heim.
"This is one manifestation of global warming," said Trenberth, one of the world's leading climate scientists. Others, including Heim, say that while global warming is real, it's difficult to blame it for the temperature change over such a short period.
Five states Â Minnesota, Wisconsin, Iowa, Massachusetts and Vermont Â set records for warmth. The 18 states that had their second warmest early winters were Kansas, Pennsylvania, Michigan, Ohio, Kentucky, Illinois, Indiana, New Jersey, Delaware, North Dakota, South Dakota, Nebraska, Maryland, Connecticut, Rhode Island, Maine, New Hampshire and New York.