NOAA found the average global temperature anomaly for March to be the warmest for any March in their records, and the third-warmest of any month since 1880 (after only the tie between Feb 1998 and Jan 2007).
Here's how warm it's been in recent months: NOAA's record year was also 2014, with an average anomaly of +0.69°C. For this year to match that record, the rest of 2015 has only to average +0.65°C, which is 0.17°C below what's it's averaged so far.
Note: NOAA uses a baseline of 1901-2000, so their numbers aren't directly comparable to GISS (1951-1980) or HadCRUT4 (1961-1990). But trends are directly comparable, as are differences between months.