I have only ever seen a ring around the sun while I have been on Isla Mujeres. That may because I am on the beach and there is nothing to block the view of the sun. It did rain early the next morning.
I did a Google search and found several articles explaining these rings.
“These rings are caused by ice crystals within thin cirrus clouds, and there several different kinds of sun rings you can see depending on the weather conditions.
One of the most common ones is called a 22Â° halo. They get this name because the ring is located 22 degrees away from the Sun itself. Both the Sun and block a 1/2 degree region of the sky at a time, so the ring around the Sun is about 44 times larger than the Sun itself.
Why do you get a ring at exactly 22Â°? The ring is formed because of the ice crystals suspended in the cirrus clouds. If you could look at the crystals under the microscope, you would see that they’re hexagonal in shape, and act as prisms for the Sun’s light. As light passes through the two sides of the prism, it’s deviated by exactly 22Â°. Since the ice crystals are jumbled up randomly in the sky, most of the light is deflected away. But from every position you’re always able to see the deflected light from some of the crystals in the sky. And this is why you see the bright ring around the Sun.”