"The combined average temperature over global land and ocean surfaces for May 2015 was the highest for May in the 136-year period of record, at 0.87°C (1.57°F) above the 20th century average of 14.8°C (58.6°F), surpassing the previous record set just one year ago by 0.08°C (0.14°F)."
"Together, the record warm March and May and fourth warmest April made the combined average temperature over global land and ocean surfaces for the March–May period (austral autumn / boreal spring) the highest on record, at 0.85°C (1.53°F) above the 20th century average of 13.7°C (56.7°F), surpassing the previous record warmth of March–May 2010 by 0.04°C (0.07°F). The Northern Hemisphere had its warmest spring on record and the Southern Hemisphere had its second warmest autumn, behind 2010."
"The first five months of 2015 were the warmest such period on record across the world's land and ocean surfaces, at 0.85°C (1.53°F) above the 20th century average, surpassing the previous record set in 2010 by 0.09°C (0.16°F)."
(Quelle)