Update: GISS has published an update
May 15, 2015: Due to an oversight several Antarctic stations were excluded from the analysis on May 13, 2015. The analysis was repeated today after including those stations.This actually made a big difference. The April temperature anomaly comes back from 0.75°C to 0.71°C, and March from 0.85°C to 0.84, making a drop of 0.13°C. GISS uses an extra Antarctic data set from GHCN, which I presume is the one involved. So this won't affect the TempLs calc.
Below the fold, as usual, I'll show the GISS plot, and the TempLS spherical harmonics smoothed map.
Here is the GISS map
And here is the TempLS spherical harmonics smoothed map:
And here is a listing of many corresponding TempLS monthly reports in recent years.