the 10 hottest yearly average temperatures have occurred in the past decade.
better wording of this would be the 10 hottest years recorded are the last 10. Soon to be 11.
I'm not sure that heat clusters over 65 years means the clusters will stay the same in the future. Going back 65 years, obfuscates the global warming acceleration that occurred since 1980, and perhaps 1998 or 2010 or 2015. At any rate, clusters would develop from a completely random process.