The phenomenon, which is also known as a 22-degree halo, is naturally occurring and not uncommon; indeed, they occur in different places around the world every year. They can occur at anytime of the year, but in this part of their world, they are more common in the spring when the northern jet stream moves south and pulls cold air from the Arctic.
Sun halos are caused by sunlight reflecting and refracting off ice crystals in cirrostratus clouds in the upper troposphere. A lunar halo can also appear around the moon.
Because the halos are caused by ice crystals in cirrostratus clouds, which can signify the approach of a weather front, they can sometimes – but not always – mean that rain is coming within a few days. Cayman’s rainy season traditionally starts mid-to-late May, so rain is entirely possible. However, the Cayman Islands National Weather Service only forecasts a 20 per cent chance of rain from now through Sunday.