I'm presenting here a visualization in the style I did for trends, and also for the November readings (more details on methods in those links). It shows GHCN V3 unadjusted station (and ERSST) anomalies for each month on a spherical projection, with mesh shading to show the anomalies. There's no grid averaging; the color for the anomaly of each station is shown. You can choose any combination of months, and it will show the average. You can orient the globe, zoom, display station data etc.
I calculated the anomalies using the TempLS offsets for the period 1951-2011. The base period is not exactly comparable to that for GISS etc, as the offsets are computed taking account of trend, and so should be fairly independent of the base time period. I'll describe below the treatment of missing data.
So here is the plot. The little map on top right is the navigator - click to mark the point you want to appear in the centre of the spherical projection. You can choose any combination of months - if you choose none, it will calculate the annual average. Whenever you want to change this choice, you must press Recalc (button above). You can zoom, and ask to see stations or mesh; to make these effective, press the Refresh button.
You can click on the main plot, and the anomaly for the nearest station will be printed on the right.
Click on this map to orient the world plot.
Missing dataOne reason why I did not post this sooner is that GHCN info trickles in, and there is still quite a lot missing for December, and for some stations a few gaps in the year. I also had to do something about another problem - many ocean sites report -1.8%deg;C when they are frozen. This is uninformative, and does not represent the air temperature, so I regarded it as missing data.