January global surface TempLS up 0.04°C from December.

The TempLS FEM anomaly (1961-90 base) was 0.886°C in January, up from 0.845°C in December.

There was again a strange sequence in the GHCN V4 monthly reports. Until last August, by about 6th of the month I would have about 3200 or so land stations reporting outside the US (ie ROW), which was enough to publish. After August, data was much more sketchy, with countries like China missing, and struggling to reach about 2600 stations. By about 10th month, I could get a reasonable result with merging JMA (Japan) data.

In January, there was suddenly an early flush of ROW data, even more than before August. But this month, by the 7th, there were only 1164 ROW stations. Then the situation improved, and now there are 3194, almost back to the old days. So I have confidence in publishing.

However, I looked into using GHCN Daily data, which is where GHCN-M comes from. I found, when GHCN-M had only 1164 stations, that the number of monthly averages I could get from GHCN-D was very dependent on how many days I insisted the month should have. 25 did not do much better than 1100, but if I relaxed to 20, I could get up to 3000. I presume that the last days of the month are coming in slowly.

So I may switch to daily to get a better idea of what is happening, and maybe post earlier. However, for now I am still using GHCN-M (+JMA)/

Here is the temperature map, using the FEM-based map of anomalies. Use the arrows to see different 2D projections.

As always, the 3D globe map gives better detail. There are more graphs and a station map in the ongoing report which is updated daily.

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 the TempLS report, usually about the 8th of the month. Then when the GISS result comes out, usually about the 15th, I discuss it and compare with TempLS. The TempLS graph uses the FEM solution on a regular near equal area grid on the sphere ; the residuals are displayed more directly using a triangular grid in a 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