Researchers at the Goddard Institute for Space Studies in New York said the finding is part of a trend in which nine of the 10 warmest years in the modern meteorological record occurred since 2000.
The average temperature around the globe in 2011 was 0.92 degrees F warmer than a mid-20th century baseline measurement, a NASA release said Thursday.
"We know the planet is absorbing more energy than it is emitting," GISS Director James E. Hansen said. "So we are continuing to see a trend toward higher temperatures. Even with the cooling effects of a strong La Nina influence and low solar activity for the past several years, 2011 was one of the 10 warmest years on record."
The first 11 years of the 21st century experienced notably higher temperatures compared to the middle and late 20th century, he said, largely sustained by increased atmospheric concentrations of greenhouse gases, especially carbon dioxide.
GISS compiled its temperature analysis using data from more than 1,000 meteorological stations around the world, satellite observations of sea surface temperature and Antarctic research station measurements, NASA said.