The Solar Ultraviolet Index (UVI) describes the level of solar UV radiation at the Earth's surface. The value of the index range from zero upward – the higher the index value, the greater the potential for damage to the skin and eye, and the less time it takes for harm to occur. The UVI vary throughout the day. Reported below is the maximum UV level (*) on a given day. This normally occurs during the six-hour period around solar noon which takes place between 11am and 4pm. The UVI is an useful indicator to avoid unnecessary exposure to ultraviolet radiation during the maximum UV level period.