Cities in more than 25 states, and the District of Columbia, broke records for average daily temperatures last month, including Chicago, Detroit, Indianapolis, Oklahoma City, Des Moines and Milwaukee.
The “year without winter” is evidence of weather variability amplified by the effectrs of greenhouse gasses on the atmosphere, according to climate scientists.
"Clearly, this is outstand dng and well outside any expectation under an unchanging climate. The magnitude and duration of the events in March certainly indicate that some unusual factors are afoot," Kevin Trenberth at the National Center for Atmospheric Research in Boulder, Colo., told LiveScience.com.
"Extremes are always expected to happen as the climate record gets longer, but certain extremes related to heating are becoming more evident," Trenberth said.
The early-year warmth has also been accompanied by abnormally high incidence of destructive tornadoes and other severe storms, including throughout March and early April.