GISS January global down 0.11°C from December.

GISS cooled, going from 0.89°C in December to 0.78°C in January (GISS report here). That is a smaller drop than TempLS mesh; I originally reported a 0.2°C fall, but later data changed that to a 0.16°C fall. GISS says that January 2018 was the fifth warmest in the record, and was cooler due to La Niña.
Update. I wrote this post based on the GISS report, as the data file was not posted for some time. It is now there, and I see that the December average has been adjusted up from 0.89°C to 0.91°C. That means the drop Dec-Jan is now 0.13°C. This brings it close to the TempLS change of 0.16°C. TempLS also incrased in December due to later data, so in both months GISS and TempLS now track well. 

The overall pattern was similar to that in TempLS. Cool in east N America and cold in far East Siberia. Very warm in west of Russia, and in the Arctic. A cool La Nina-ish plume, but warm in the Tasman sea and nearby land. The W US was warm, more so than TempLS showed. Also the W Russia hotspot extended well into central Europe.

As usual here, I will compare the GISS and previous TempLS plots below the jump.

Here is GISS


And here is the TempLS spherical harmonics plot

This post is part of a series that has now run for six years. The GISS data completes the month cycle, and is compared with the TempLS result and map. GISS lists its reports here, and I post the monthly averages here.
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