According to the NOAA, October 2015 was not only the warmest October on record, globally, but the “greatest above-average departure from average for any month”. The previous record was set in October 2014.
Additionally, the January-October average is the highest on record, surpassing the previous record set last year.
Click the image at right to see it larger. It notes the following: In both the contiguous U.S. and Alaska, October 2015 was the fourth-warmest October on record. Parts of Europe saw their driest Octobers on record. Residents of Africa and Australia saw the warmest Octobers on record. (At the same time, other places were cooler than average, including southern South America, which posted several record lows, and Russia.)
Locally, by my own measurements, October 2015 and October 2014 tied for warmest.