28 April 2011. 22º radius halos are visible all over the world and throughout the year. Visible whenever the sky is wisped or hazed with thin cirrus clouds which contain ice crystals in even the hottest climes. This image was captured in the 25C heat of the Portuguese Med. The halo is always the same diameter regardless of its position in the sky. Captured with Olympus E5 & 12-60mm SWD lens.
High cirrostratus cloud forms the halo on the advancing edge of warm fronts with their associated rain. Many halos are not associated with frontal systems and to see one is not a reliable sign of bad weather. They are things of beauty, not bad news.
22 radius halosuncirrostratusweatheropticalmark humpageolympusE5