U.N. climate experts say the first decade of the new millennium was an unprecedented era of climate extremes, with more countries than ever before seeing their temperature records broken.

The World Meteorological Organization's analysis Wednesday says average land and ocean surface temperatures during 2001-2010 rose from the previous decade and were up almost a half-degree Celsius from the 1961-1990 global average.

The U.N. agency cites heatwaves in Europe and Russia, droughts in the Amazon Basin, Australia and East Africa, and huge storms like Tropical Cyclone Nargis and Hurricane Katrina.

Its survey of data from 139 nations shows that floods like those in Pakistan, Australia, Africa, India and Eastern Europe were the most frequent extreme weather events.