One reason last month's GISTEMP was so high is that the Southern Hemisphere was its warmest ever: +0.85°C above the 1951-1980 baseline.
That shattered the previous SH record of +0.79°C in August 1996.
By the way, 81% of the southern hemisphere's surface is ocean, whereas only 61% of the northern hemisphere is. So 57% of the world ocean surface lies in the southern hemisphere.
Only about 11% of the world's population lives in the southern hemisphere, meaning the NH has 8.1 times the population of the SH and 3.9 times the population density. You can see why the Nazis went there to hide.