The combined average temperature over global land and ocean surfaces for October 2015 was the highest temperature for any October in the 136-year period of record since 1880, at 0.98°C (1.76°F) above the 20 century average of 14.0°C (57.1°F), according to NOAA.
October 2015 was the sixth consecutive month a monthly global temperature record has been broken.
It was also the greatest departure from average for any month in the 1630 months of record-keeping (since 1880), surpassing the previous record high departure set just last month by 0.13°F (0.07°C).
The first 10 months of 2015 comprised the warmest such period on record across the world's land and ocean surfaces, at 0.86°C (1.55°F) above the 20 century average, surpassing the previous record of 2014 by 0.12°C (0.22°F).
This margin is larger than the uncertainty associated with the dataset.
To date, eight months this year have been record warm for their respective months.
The exceptions were: January was the second warmest January on record and April third warmest.