December global surface TempLS up 0.12°C from November.

The TempLS mesh anomaly (1961-90 base) was 0.748deg;C in December vs 0.628°C in November. That continues the recent up-down alternation, and makes it the third warmest December in the record (near tie with 2017 for 2nd). The GHCN results were delayed by the US government hiatus.

Significantly, for the second month in a row, SST was down, after a few months of rise. But land temperatures were generally higher. The big contributors to this were N America and the Arctic. Almost everywhere was warm, including Europe and Australia. A cool patch in mid-Siberia/Mongolia.
Here (from here) is the plot of relative contributions to the rise (ie components weighted by area):

Here is the temperature map. As always, there is a more detailed active sphere map here.

This post is part of a series that has now run since 2011. The TempLS mesh data is reported here, and the recent history of monthly readings is here. Unadjusted GHCN is normally used, but if you click the TempLS button there, it will show data with adjusted, and also with different integration methods. There is an interactive graph using 1981-2010 base period here which you can use to show different periods, or compare with other indices. There is a general guide to TempLS here.

The reporting cycle starts with a report of the daily reanalysis index on about the 4th of the month. The next post is this, the TempLS report, usually about the 8th. Then when the GISS result comes out, usually about the 15th, I discuss it and compare with TempLS. The TempLS graph uses a spherical harmonics to the TempLS mesh residuals; the residuals are displayed more directly using a triangular grid in a better resolved WebGL plot here.

A list of earlier monthly reports of each series in date order is here:

1. NCEP/NCAR Reanalysis report
2. TempLS report
3. GISS report and comparison with TempLS