2014: Hottest May on record.

Says who? Says the US Government -

http://www.ncdc.noaa.gov/sotc/global/2014/5

The combined average temperature over global land and ocean surfaces for May 2014 was record highest for this month, at 0.74°C (1.33°F) above the 20^th century average of 14.8°C (58.6°F).