Clear-sky UV index for 21 Apr 2019
With a thinner ozone layer and a higher position of the sun in the sky more ultraviolet radiation will reach Earth’s surface. The clear-sky UV index is the effective UV irradiance (1 unit equals 25 mW/m²) reaching the Earth’s surface. The clear-sky UV index is based on the CIEaction spectrum for the susceptibility of the caucasian skin to sunburn (erythema) and it is valid for cloud-free conditions at local solar noon. Forecasts are provided for today and the next few days.