WASHINGTON - It may be cold comfort during a frigid February, but last month was by far the hottest January ever.
The broken record was fueled by a waning El Nino and a gradually warming world, according to U.S. scientists who reported the data Thursday. Records on the planet's temperature have been kept since 1880.
Spurred on by unusually warm Siberia, Canada, northern Asia and Europe, the world's land areas were 3.4 degrees Fahrenheit warmer than a normal January, according to the U.S. National Climatic Data Center in Asheville, N.C. That didn't just nudge past the old record set in 2002, but broke that mark by 0.81 degrees, which meteorologists said is a lot, since such records often are broken by hundredths of a degree at a time.
"That's pretty unusual for a record to be broken by that much," said the data center's scientific services chief, David Easterling. "I was very surprised."
The scientists went beyond their normal doublechecking and took the unusual step of running computer climate models "just to make sure that what we're seeing was real," Easterling said.
"From one standpoint it is not unusual to have a new record because we've become accustomed to having records broken," said Jay Lawrimore, climate monitoring branch chief. But January, he said, was a bigger jump than the world has seen in about 10 years.
The temperature of the world's land and water combined - the most effective measurement - was 1.53 degrees Fahrenheit warmer than normal, breaking the old record by more than one-quarter of a degree. Ocean temperatures alone didn't set a record.
In the Northern Hemisphere, land areas were 4.1 degrees Fahrenheit warmer than normal for January, breaking the old record by about three-quarters of a degree.
But the United States was about normal. The nation was 0.94 degrees Fahrenheit above normal for January, ranking only the 49th warmest since 1895.
The world's temperature record was driven by northern latitudes. Siberia was on average 9 degrees Fahrenheit warmer than normal. Eastern Europe had temperatures averaging 8 degrees Fahrenheit above normal. Canada on average was more than 5 degrees warmer than normal.
Larger increases in temperature farther north, compared to mid-latitudes, is "sort of the global warming signal," Easterling said. It is what climate scientists predict happens and will happen more frequently with global warming, according to an authoritative report by hundreds of climate scientists issued this month.
Meteorologists aren't blaming the warmer January on global warming alone, but they said the higher temperature was consistent with climate change.
Easterling said a weakening El Nino - a warming of the central Pacific Ocean that tends to cause changes in weather across the globe - was a factor, but not a big one. But Kevin Trenberth, director of climate analysis at the National Center for Atmospheric Research, said El Nino made big changes worldwide that added up.
Temperature records break regularly with global warming, Trenberth said, but "with a little bit of El Nino thrown in, you don't just break records, you smash records."
As much of the United States already knows, February doesn't seem as unusually warm as January was.
"Even with global warming, you're not going to keep that cold air bottled up in Alaska and Canada forever," Easterling said.