Update There was a major revision to GHCN China data, and now March was 0.03°C warmer than February. See update post
TempLS mesh declined in March, from 0.861°C to 0.795°C. This follows the very small drop of 0.01°C in the NCEP/NCAR index, and larger falls in the satellite indices. The March temperature was still warm, however. It was higher than January (just) and higher than any month before October 2015. And the mean for the first quarter at 0.813°C is just above the record high annual mean of 0.809°C, though it could easily drop below (or rise further) with late data. So far all the major countries seem to have reported. With that high Q1 mean, a record high in 2017 is certainly possible.
TempLS grid also fell by a little more by 0.11°C. The big feature this month was the huge warmth over Siberia. It was cold in Canada/Alaska (but warm in ConUS) and cold in China. Here is the map:
The breakdown plot is remarkable enough that I'll show that too here (it's always on the regular report). On land almost all the positive contribution came from Siberia and Arctic - without that, it would have been quite a steep fall. SST has been slowly rising since December, which is another suggestion of a record year possibility.
Incidentally I'm now using the finer and more regular SST mesh I described here. The effect on results is generally small, of order 0.01-02°C either way, which is similar to the amount of drift seen in late data coming in. You may notice small differences in comparing old and new. You'll notice quite a big change in the number of stations reporting, which is due to the greater number of SST. I've set a new minimum for display at 5300 stations.