NOAA Confirms - May 2016 13th Consecutive Hottest Month Ever; 1.57F Above 20th Cent. Average
Temperatures
In the atmosphere, 500-millibar height pressure anomalies correlate well with temperatures at the Earth's surface. The average position of the upper-level ridges of high pressure and troughs of low pressure—depicted by positive and negative 500-millibar height anomalies on the May 2016 and March–May 2016 maps—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.
The combined average temperature over global land and ocean surfaces for May 2016 was the highest for May in the 137-year period of record, at 0.87°C (1.57°F) above the 20th century average of 14.8°C (58.6°F), besting the previous record set in 2015 by 0.02°C (0.04°F). May 2016 marks the 13th consecutive month a monthly global temperature record has been broken—the longest such streak since global temperature records began in 1880.
The May 2016 global land and ocean surface temperature departure from average was also the lowest monthly temperature departure from average since August 2015 and, unlike the past five consecutive months (December 2015 through April 2016), did not surpass 1.0°C (1.8°F). May 2016 tied with June 2015 and August 2015 as the 12th highest monthly temperature departure among all months (1,637) on record. Overall, 13 of the 15 highest monthly temperature departures in the record have all occurred since February 2015, with February 1998 and January 2007 among the 15 highest temperature departures.
The average global temperature across land surfaces was 1.17°C (2.11°F) above the 20th century average of 11.1°C (52.0°F)—the third highest May temperature on record, behind 2012 (+1.26°C / +2.27°F) and 2015 (+1.21°C / +2.18°F). This was also the lowest land monthly temperature departure from average since September 2015, which had a temperature departure of 1.14°C (2.05°F) above average.
May 2016 was characterized by warmer to much warmer than average conditions across Alaska, Canada, Mexico, Central America, northern South America, northern Europe, Africa, Oceania, and parts of southern and eastern Asia, according to the Land & Ocean Temperature Percentiles map above. Areas with record warmth included much of Southeast Asia and parts of northern South America, Central America, the Caribbean, the Middle East, and northern and eastern Australia. Near- to cooler-than-average conditions were present across much of the contiguous U.S., central and southern South America, and much of central Asia. No land areas experienced record cold temperatures during May 2016. According to NCEI's Global Regional analysis, five of the six continents had at least a top nine warm May, with Oceania observing a record high average temperature for May since continental records began in 1910.
EDIT
http://www.ncdc.noaa.gov/sotc/global/201605
