The ocean surface temperature was the warmest on record for July, according to the National Oceanic and Atmospheric Administration (NOAA) in the US.
Global ocean surface temperatures reached 62.56 degrees F in July 2009, just over 1 degree F higher than the 20th century average of 61.5 degrees F (16.4 degrees C).
Land surface temperatures across the world were tied with 2003 as the ninth-warmest July on record, just under 1 degree F above the 20th century average of 57.8 degrees F (14.3 degree C).
The combined land and ocean surface temperatures for the month were the fifth-warmest since world-wide records began in 1880.
NOAA data also showed that the Arctic sea ice coverage was 12.7 per cent below the 1979-2000 average in July 2009. This is the third lowest July sea ice extent on record after 2007 and 2006.
Antarctic sea ice coverage in the same month was 1.5 per cent above the 199-2000 average.
The NOAA said July Arctic sea ice extent had decreased by 6.1 percent per decade since 1979, while July Antarctic sea ice extent had increased by 0.8 percent per decade over the same period.