When light travels through a medium with a changing refractive index, it gets bent towards its higher values. This can produce upside down "mirror" images of a scenery in deserts, over heated roads or above bodies of water. We built a model for the temperature profile based on measurement data, from which we calculated the refractive index of air using another model. We implemented a computer program, which simulates mirages above water using the method of ray tracing. Rays of light are traced by solving the eikonal equation using different Runge-Kutta methods. We developed a simple extension of the Runge-Kutta method to efficiently check ray intersection with an arbitrary geometry. Given a picture, a physical setup and a value for both the temperature of the water body and that of the ambient air sufficiently far from the surface (where it can be considered constant), our program can realistically reproduce images of photographed mirages.