Weather is weather and has been in flux, since there was life on this planet.
In the Northern Hemisphere, most places have seasons ( at least 2 and I don't mean "wet" and "dry", like in India ) and in the Southern Hemisphere, they are reversed. Of course there have been changes and interruptions of the norm; many due to volcanic eruptions. But THAT isn't what is meant by "CLIMATE CHANGE" in this day and age....sadly.
Perhaps that's one of the reasons why Mattis thinks that human activity is NOT a primary contributor to the global warming that we see.