The UV index is an international standard measurement of how strong the ultraviolet (UV) radiation from the sun is at a particular place on a particular day. Its purpose is to help people to effectively protect themselves from UV light, which causes sunburns, eye damage such as cataracts, skin aging, and skin cancer (see the section health effects of ultraviolet light). Public-health organizations recommend that people protect themselves (for example, by wearing sunscreen and a hat) when the UV index is 3 or higher; see the table below for complete recommendations.
The UV index announced in weather forecasts is a prediction of how strong the actual UV intensity will be at the sun's highest point in the day, which typically occurs during the four-hour period surrounding solar noon. The prediction is made by a computer model that accounts for the effects of altitude and inclimate weather (clouds), which increase or decrease, respectively, the amount of UV radiation that will reach the surface. The calculations are weighted in favor of the UV wavelengths that human skin is most sensitive to. Providing the public with an easy-to-understand daily forecast of UV intensity is the main purpose of the UV index.
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Australia UVI maps - Updated daily. From SafeSun.
Meta Description: [ UV Index (UVI) map. World, US, Australia, New Zealand. Find ultraviolet (UV) intensity in your area. Updated daily. ]
Seriously Shady - UV index, information on ultraviolet rays- how to protect yourself.
USA Ultraviolet Index - Selected Cities. From NOAA.
WeatherPro - Ultraviolet Index - Offers up to date UV index information for selected US cities.