This year is forecast to be among the top 10 hottest years on record, Britain's weather office said Thursday, despite a strong cooling effect predicted from the tropical weather phenomenon known as La Nina.

The global surface temperature in 2008 will rise 0.67 degrees above what climate scientists call the long-term average of 57.2 degrees, the Met Office said. The average is derived by calculating the mean of surface temperatures registered globally between 1961 and 1990.

That would be enough to have it rank among the hottest years on record, although the Met Office said would be unlikely to beat the current warmest year of 1998, which was 0.94 degrees above the long-term average.

The Met Office said a powerful La Nina, the name given to the upwelling of large areas of cold water in the tropical Pacific Ocean, would probably keep 2008's temperature from breaking the global record. But it said the underlying trend of higher and higher temperatures was likely to continue.

"Phenomena such as El Nino and La Nina have a significant influence on global surface temperature and the current strong La Nina will act to limit temperatures in 2008," said Chris Folland, a climate scientist at the Met Office's Hadley Center in Exeter, southwest England. "Sharply renewed warming is likely once La Nina declines."

The Met Office said the world's hottest years on record were 1995, 1997, 1998, and every year since 2000. Its global temperature records stretch back to 1850.