This is physics 101, warm air can hold more water at the same relative humidity. When air is warmed it collects humidity, and when the humidity condenses to water, it cools, and the cascading effect is bigger proportionally to the increased level of water in the air.

Even I figured that out more than 10 years ago, without being a climate scientist, but based on basic physics.
And in my country, we’ve also been seeing it clearly for some years now, and most regions are expanding sewage systems to be able to handle it.

But of course climate change deniers probably couldn’t figure such things out, and need it explained as you would to a child.