People walk along the Mall during warm weather on February 23. A new study links the month’s warm weather to man-made climate change. (Brendan Smialowski/AFP via Getty Images)

March has provided an unexpected dose of winter, but a freakishly balmy February broke more than 11,700 local daily records for warmth in the United States.

The average temperature last month was 41.2 degrees — 7.3 degrees warmer than normal but three-tenths a degree behind the record, the federal National Oceanic and Atmospheric Administration reported last week.

Oklahoma hit 99 degrees, Chicago, Illinois, had no snow and it was unseasonably toasty for most of the country east of the Rocky Mountains. A cool Pacific Northwest kept the national record from falling, said NOAA climate scientist Jake Crouch.

An international science team calculated that man-made global warming tripled the likelihood for the nation’s unusually warm month. The team, known as 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 of a world without heat-trapping gases.

“I don’t recall ever seeing a February like this,” said Princeton University climate scientist Gabriel Vecchi, who was part of the World Weather Attribution team that performed the study. “We expect this to happen with more and more frequency over time.”

Magnolia trees bloomed early in Washington this year. Flowering trees, including the city’s beloved cherry blossoms, are at risk of dying during the March frost. (Cliff Owen/AP)

Several outside scientists praised the 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.

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 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.