Explanation:
The UV index scale is measurement of the strength of harmful ultraviolet radiations of the sun and its effects on the human skin upon direct exposure .
This scale is recognized by the international health organization, and its varies from 0 to 11 , it is the normalized intensity radiation from the sun , that comes through the upper atmosphere , a UV scale reading 0 to 2.9 means a safer radiation levels, whereas 3 to 5.9 claims moderate risk but above 6 alarms a warning case and skin and eyes are needed to be protected .
The UV index scale normally ranges 0 to 11 .