The fast displacement of Batman creates a lower pressure that causes condensation by adiabatic effect. This is similar to the contrails you can see from airplanes. From a graphical point of view, this is unfortunate because, rendering the tall skyscrapers of the city, using a strong contrast given by a direct sunlight, would be a delight for the illustrator. We should perhaps ask Robin to talk to Batman and ask him to move slower. What do you think?

Because when you're making a tv show, or a movie, sunny skies means things are going well (or the main character thinks it does), cloudy = ominous or bad , rain = sad or crying. Not a lot of good **** goes down in Gotham...hence the lack of tans.

Cloudiness adds more of a dramatic effect in tv shows and films. Gotham is portrayed as a gloomy city, thus the always darkness and/or cloudiness.

It's cause humidity & lots of water bearing.

It is due to coldness and lots of water uses

because they put Batman where the sun doesnt shine