The global temperature for 2020 was 0.88C equaling that in 2016 based on GHCN-V4C (homogenised) and HadSST3. The V4U (uncorrected) result is 0.82C for 2020 making it slightly cooler than 2016. These are based on the Spherical Triangulation technique described here.
December saw a large drop in global temperatures relative to November mainly due to a strong La Nina developing in the South Pacific.
The monthly time series looks as follows.
Nick Stokes (TempLS) uses a similar algorithm but with a loess interpolation. It is interesting to compare his results to mine. I think he is using only the uncorrected V4U data combined with ERSST sea surface temperatures.
|Nov 2020||0.891||Ave 2016||0.857|
|Dec 2020||0.628||Ave 2020||0.852|
My Uncorrected V4U/HadSST3
|Nov 2020||0.941||Ave 2016||0.838|
|Dec 2020||0.645||Ave 2020||0.818|
My Corrected V4C/HadSST3
|Nov 2020||0.960||Ave 2016||0.880|
|Dec 2020||0.655||Ave 2020||0.887|
There are some small systematic differences between the results, but we can draw the following conclusions.
- 2020 reached the same temperature as 2016.
- There was a significant drop in temperature in December due to a strong La Nina.
- Consequently 2021 should start cooler