Global temperatures in October, as well as for the entire calendar year so far, were the hottest on average since record-keeping began in 1880, the US government said Thursday.
It was the 38th consecutive October in which global average temperatures were higher than the average for the 20th century, the National Oceanic and Atmospheric Administration (NOAA) reported.
"The January-October combined global land and ocean average surface temperature was the warmest such period on record, surpassing the previous record set in 1998 and 2010," NOAA said.
The combined average temperature over land and ocean surfaces in October was 58.43 degrees Fahrenheit (14.74 degrees Celsius), which beat the previous record for the month by 0.02 degrees Fahrenheit (0.01 degrees Celsius).
Warmer than average temperatures were recorded over most of the Earth's land surface, except for large parts of Central Asia.
"Record warmth was notable across a large area of southern South America, the US western coastal regions, Far East Russia, parts of southern and southeastern Asia, much of southern and western Australia, and parts of southern Europe," it said.
The average October temperatures globally over land alone were the month's fifth highest on record.
The global sea surface temperature was 61.72 degrees Fahrenheit in October, the highest on record for the month and the sixth consecutive monthly high, NOAA said.
"Record warmth was observed in parts of every major ocean basin. Nearly all of the Indian Ocean was record warm or much warmer than average, it said."
- Polar sea ice shrinks -In the Arctic, the average extent of sea ice in October was the sixth smallest for the month since record-keeping began in 1979.
Antarctic sea ice also declined in October, ending a string of six consecutive months of increasing sea ice in the region.
Australia experienced its second warmest October since records began in 1910, behind only 1998, with record-high maximum daytime temperatures that averaged 4.97 degrees Fahrenheit above the 1961-1990 average, NOAA said.
"Several countries in Europe reported October temperatures among their 10 warmest, including France, Switzerland, the United Kingdom, Denmark, Germany, and Austria," it added.
The contiguous United States meanwhile observed its fourth warmest October since national records began, at 3.0°F (1.7°C) above the 20th century average, the federal agency said.
UN climate experts have cautioned there is no time to lose in the battle against global warming, which UN Secretary General Ban Ki-moon has labelled "the defining issue of our times".
Earlier this month, the UN Intergovernmental Panel on Climate Change warned that time is running out to limit warming to two degrees Celsius (3.6 degrees Fahrenheit) by 2100 from pre-industrial levels.
It said Earth is on a trajectory to warm up by at least four degrees Celsius -- a recipe for melting ice caps, extreme weather, habitat and species loss and conflict for resources.
After years that saw little progress in climate talks, the world's two biggest economies and top polluters, China and the United States, agreed on November 12 to new targets for lowering their respective greenhouse gas emission.
Leaders of the 28-nation European Union, the third-largest greenhouse gas producer, have meanwhile pledged to cut its emissions by at least 40 percent by 2030 from 1990 levels.