WASHINGTON  The decade ending in 2009 was the warmest on record, new surface temperature figures released Thursday by the National Aeronautics and Space Administration show.

The agency also found that 2009 was the second warmest year since 1880, when modern temperature measurement began. The warmest year was 2005. The other hottest recorded years have all occurred since 1998, NASA said.

James E. Hansen, director of NASA’s Goddard Institute for Space Studies, said that global temperatures varied because of changes in ocean heating and cooling cycles. “When we average temperature over 5 or 10 years to minimize that variability,” said Dr. Hansen, one of the world’s leading climatologists, “we find global warming is continuing unabated.”

A separate preliminary analysis from the National Climatic Data Center, a unit of the National Oceanic and Atmospheric Administration, found that 2009 tied with 2006 as the fifth warmest year on record, based on measurements taken on land and at sea. The data center report, published earlier this week, also cited the years 2000 to 2009 as the warmest decade ever measured. The new temperature figures provide evidence in the scientific discussion of global warming but are not likely to be the last word on whether the planet’s temperature is on a consistent upward path.