The global average temperature anomaly for October was 0.706C, which is a fall of 0.15C from September. This reduces the annual average so far to 0.9C leaving 2020 still slightly higher than 2016. However the uncorrected data (without pair-wise homogenisation) leave 2020 just below 2016. My calculation of the global temperature anomaly is based on GHCN V4 and HadSST3 using a 3D spherical triangulation method and a baseline of 1961-1990.
The monthly data below shows a large drop in temperatures for October
The spatial distribution below shows lower than average temperatures across North America., Central Asia and Western Europe. Blue colours show temperatures below the 1961-1990 average for October.
There were also cooler ocean temperatures in the Southern Hemisphere.
I have noticed an interesting effect of the pair-wise homogenisation process. Recent months seems to show a large divergence between the corrected and uncorrected GHCN V4 results. However this difference slowly decays with time so that past differences reduce. This is because the corrected data from previous months and years also slowly change as the homogenisation algorithm is rerun each month. This seems to produce a self correcting process tending to reduce strong discrepancies. over time.