GLOBAL temperatures got another kick along last month, with September easily the hottest in records going back to 1891, Japan's Meteorological Agency said.
According to preliminary data for the month, average sea and land surface temperatures in September were 0.5 degrees above the 1981-2010 average.
That compared with the previous record set only a year earlier, with an anomaly of 0.35 degrees.
Each of the last four Septembers have set records for the month, the agency said.
Japan's reading is likely to be confirmed by other agencies in coming days, such as the US National Oceanic and Atmospheric Administration (NOAA).
Last month, NOAA said August was the sixth month in 2015 alone to set global temperature records.
With September likely to have made it seven record months, 2015 is well on course to setting a new mark as the hottest year, eclipsing 2014.
Driving the surge in global surface temperatures this year is the powerful El Nino weather event that continues to intensify in the Pacific.
During El Nino years, the world's oceans tend to absorb less heat as wind patterns change across the equatorial Pacific, lifting global temperatures by about 0.1-0.2 degrees.
That boost adds to the background warming from climate change, which has seen temperatures rise about 0.9 degrees over the past century, climatologists say.
The likelihood of another record warm year comes just over a month before delegates from about 200 nations will gather in Paris, France, to negotiate a climate treaty aimed at limiting the temperature increase from greenhouse gas emissions to within two degrees of pre-industrial levels.