The UV Index is a forecast of the probable intensity of skin damaging ultraviolet radiation reaching the surface during the solar noon hour (11:30-12:30 local standard time or 12:30-13:30 local daylight time). The greater the UV Index the greater the amount of skin damaging UV radiation. How much UV radiation is needed to actually damage one's skin is dependant on several factors. However, in general the darker one's skin (that is the more melanin one has in his/her skin) the longer (or the more UV radiation) it takes to cause erythema (skin reddening). It is widely believed that many abnormalities of skin, such as various cancers, are directly related to cumulative exposure of UV light. As the quality of the ozone layer decreases, there is cause for concern that the cumulative exposure to damaging wavelengths of UV light will continue to increase thus causing an increase in the incidence of skin disorders.