Ultraviolet Radation IndexVariable Name ⤴

The global solar UV index (UVI) was developed as an easy-to-understand measure of biologically effective UV radiation with a view to promote public awareness of the risks of UV radiation exposure and sun protection. In the initial work done on UVI in Canada, a typical midday summer erythemal irradiance of 250 mW.m-2 was found leading to the (arbitrary) definition of one UV index equal to an erythemally weighted irradiance of 25 mW.m-2. This gives a typical range of UVI 0 to 11+.