International standard; it is the forecast of the quality of the UVAs and UVBs at ground level. It provides information on the intensity of the UVs and on the recommendations and behaviour to adopt to protect oneself from their dangerous effects

Abbreviation of Ultraviolets A, electromagnetic waves of the light spectrum between 100 and 400 nm. The UVA are particularly responsible for the ageing of the skin and skin cancer or melanoma.

Abbreviation of Ultraviolets B, electromagnetic waves of the light spectrum between 100 and 400 nm. The UVB are particularly responsible for sunstroke.