The UV Index (UVI) is an international standard measurement that indicates the strength of sunburn-producing ultraviolet (UV) radiation at a specific place and time. It is a linear scale starting from zero (no UV radiation, such as at night) and can go above 11 in extreme conditions, with higher values indicating greater potential for skin and eye damage and less time needed for harm to occur
. The UV Index helps people understand the risk of UV exposure and encourages protective measures like using sunscreen, wearing hats, and sunglasses. It is primarily used in daily weather forecasts to inform the public about the intensity of UV radiation around solar noon, when the sun is highest in the sky
. The scale is color-coded to represent different exposure levels:
- Low (1-2, green)
- Moderate (3-5, yellow)
- High (6-7, orange)
- Very High (8-10, red)
- Extreme (11+, violet)
Higher UV Index values mean faster skin damage and higher risk of sunburn, skin cancer, and eye damage such as cataracts. The UV Index was developed by Canadian scientists in 1992 and standardized by the World Health Organization (WHO) and other international bodies to promote sun safety worldwide
. In summary, the UV Index is a forecasted number that indicates how intense UV radiation is expected to be, helping people take appropriate sun protection measures to reduce health risks from UV exposure
