@Vladislav-Iaroshchuk I don't care all that much about reporting on Windy (it's kind of our third option for viewing the weather station data) and the spec leaves things open to interpretation.
Now, let's say you are driving in a car and you have a speedometer. Should that dial show your sliding distance traveled in the past hour or should it show your speed at the moment you read it? That's why I think a sliding one hour average of rainfall is less than helpful.
What's worse, unless you can go indefinitely far back in history to a point where the average rainfall was zero, there's no way for you to derive the instantaneous rainfall from an hourly sliding average.
If I'm looking at the data as a human, I want to see at a glance if the rain seems to have ended. A declining average might tell you that it has ended, but it might also mean that it's raining less. A per minute graph is more helpful.