The monthly anomaly of the global average surface temperature in August 2017 (i.e. the average of the near-surface air temperature over land and the SST) was +0.39°C above the 1981-2010 average (+0.73°C above the 20th century average), and was the 3rd warmest since 1891. On a longer time scale, global average surface temperatures have risen at a rate of about 0.68°C per century.
1st. 2015(+0.46°C), 2nd. 2016(+0.43°C), 3rd. 2017(+0.39°C), 4th. 2014(+0.33°C), 5th. 1998(+0.28°C)