It's an oscillation. They give each other heat. But El Nino releases it for most of the world to choke on, versus La Nina keeps it trapped in the WPAC subsurface. I think most of us would prefer the latter except select people who want some more snow in their backyards by making the rest of the world torch to push the troughing their way. La Nina and -PDO were actually hiding some of the effects of global warming (not very well either). Now that it's getting released it's just going to become more apparent.

May Gray has arrived right on schedule

And where does the "warmth" that La Nina supposedly generate come from? The logic doesn't follow.

May of 2018 started off like this. Then it got very hot for the second half.

The Architecture is prestigious and something that I'd like to see in person myself. Enjoy the rest of your trip and thanks for sharing these photos.