A freakishly balmy February broke more than 11,700 local daily records for warmth in the United States, but it didn't quite beat 1954 for the warmest February on record, climate scientists said.
The average temperature last month was 41.2 degrees -- 7.3 degrees warmer than normal but three-tenths a degree behind the record, the National Oceanic and Atmospheric Administration reported Wednesday.
It was unseasonably toasty for most of the country east of the Rockies, but a cool Pacific Northwest kept the national record from falling, said NOAA climate scientist Jake Crouch.
Chicago had no snow. Oklahoma hit 99 degrees. Texas and Louisiana had their hottest February. NOAA said local weather stations broke or tied warm temperature records 11,743 times but set cold records only 418 times.
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An international science team's computer analysis of causes of extreme weather calculated that man-made global warming tripled the likelihood for the nation's unusually warm February. The mostly private team of researchers, called World Weather Attribution, uses accepted scientific techniques to figure if climate change plays a role in extreme events based on computer simulations of real world conditions and those without heat-trapping gases.
"I don't recall ever seeing a February like this," said Princeton University climate scientist Gabe Vecchi, who was part of the quick attribution study that was not peer reviewed. "We expect this to happen with more and more frequency over time."
Several outside scientists praised the quick study including Pennsylvania State University meteorology professor David Titley, who was on a National Academy of Sciences panel that certified the accuracy of climate change attribution science.
"This is the new climate normal that we all need to come to grips with," Titley said. "And it's stunning how quickly our climate has changed."
Natural random weather variations and climate change combined to make it a weird February, meteorologists said. Overall, NOAA said it was the sixth warmest U.S. winter on record, about 3.7 degrees warmer than the 20th century average.
"You definitely do feel that this is going to be something that you get to enjoy now and you pay for after the fact," said Vecchi, who was biking in short-sleeves in New Jersey last month.
Oklahoma University meteorology professor Jason Furtado said he worries that the lack of deep Arctic cold plunges in February means the Gulf of Mexico never cooled down. And when severe weather season in the spring starts, the moisture coming north from warmer Gulf waters will goose outbreaks and increase the probability of nasty spring storms and tornadoes. Massachusetts already had an unprecedented February tornado.
A March frost could kill early blooming trees and flowers and the lack of a proper winter could lead to more mosquitoes and ticks this year, Vecchi said.
"What is lurking behind the corner while we're outside throwing a Frisbee might be looking to make our lives less pleasant," he said.