Mirages are light diffusion as a result of heat. The most well-known ones are in the desert.
There is also heat haze. You see this on roads and other places.
There are different types of mirages and technical explanations. The details are beyond me. You are on your own.
We are in the midst of a heat wave in the US. They say it will break on Saturday. Uh, huh. I’ll believe it when I see it.
All of the pictures are from Wikimedia Commons.
Two pictures of heat haze.
Heat haze from jet engines by, Mean as custard.