
(The above graph shows how temperatures have shifted outside of 20th Century ranges. During 2014-2017, the world dramatically warmed — generating further rightward movement in the bell curve. Temperature has an impact on everything from drought, to the severity of thunderstorms, to the length and intensity of fire season, to the fuel available for the most powerful hurricanes, to algae blooms, to coral bleaching events. Image source: NASA GISS.)
As you can see, there are still cool summers but hot summers outweigh them.
If you want to know why this summer is so hot so early, this “blob” is the reason:

The hot southern seas will see more coral bleaching:

Read the article by respected blogger “Robert Scribbler;”
https://robertscribbler.com/2017/12/21/australias-hot-ocean-blob-fuels-record-heat-extreme-weather-risk-to-coral-reefs/#comments