GlobalUV app for iPhone and iPad

This app shows UVI levels for any location in the world.

The UV Index (UVI) is a measure of skin-damaging ultraviolet radiation. This App provides estimates of the current UVI and how it is expected to vary throughout this day at your current location, or at other selectable locations throughout the globe. Although small amounts of UV radiation are beneficial to health, overexposure can lead to skin cancer. The main determinant of UVI is the suns elevation angle. UVI values are thus greatest in the summer, especially near solar noon. At mid-latitudes, peak UVI can reach summer peak values greater than 10, but in winter, the UVI values are generally less than 1. Peak UVI values can exceed 20 in the tropics, where seasonal variations are much smaller. The highest values in the world occur in the high altitude Altiplano region of South America, where they can exceed UVI=25.