From the Copernicus Program Climate Change Service:
Globally, October was 0.69°C warmer than the average October from 1981-2010, making it by a narrow margin the warmest October in this data record. Europe generally saw above-average temperatures, with the exception of most of the north and north-west of the continent. Temperatures were much above average in large parts of the Arctic, while much of western USA and Canada experienced much below average temperatures.
October temperatures in 2019 were above the 1981-2010 average for most of Europe, especially so in the east and south-east. Below-average temperatures occurred over most of the north and north-west of the continent.
Elsewhere, temperatures over the northern hemispheric land masses were markedly above average over parts of the Arctic, over the eastern USA and Canada, and over the Middle East and much of North Africa and Russia. Temperatures were likewise well above average over southern Brazil, southern Africa, western and southern Australia, and most of eastern Antarctica.
Temperatures over land were substantially below average over a region encompassing much of the western USA and Canada. They were also below average in parts of tropical Africa and Antarctica, and to a lesser degree over several other regions.
Regions of below-average temperature occurred over all major oceans, including the tropical eastern Pacific and the ice-covered Weddell Sea. Air temperatures over sea were nevertheless predominantly higher than average, especially so over several Arctic and Antarctic seas and over the north-eastern Pacific Ocean.
Global temperatures were substantially above average in October 2019. The month was:
0.69°C warmer than the average October from 1981-2010, making it by a narrow margin the warmest October in this data record; an insignificant 0.01°C warmer than October 2015, the second warmest October; 0.09°C warmer than October 2017, the third warmest October.