Last year tied with 2005 as the warmest year on record

The Earth in 2010 experienced temperatures higher than the 20th century average for the 34th year in a row, the National Oceanic and Atmospheric Administration said. Last year was the wettest on record, NOAA said citing Global Historical Climatology Network which made the calculation based on global average precipitation, even though regional patterns varied widely.

The analysis also tracked weather changes that contributed to massive floods in Pakistan and a heat wave in Russia, saying an "unusually strong jet stream" from June to August was to blame.

A separate report by Canada's Environment Ministry said that last year was the warmest in Canada since it began keeping meteorological records 63 years ago.

NASA analysts said the shrinking sea ice in the Arctic may have made winters in Europe and Canada warmer than usual. "Arctic sea ice acts like a blanket, insulating the atmosphere from the ocean's heat. Take away that blanket, and the heat can escape into the atmosphere, increasing local surface temperatures. Regions in northeast Canada were more than 18 degrees (F) warmer than normal in December.