What does the UV Index measure?

The UV Index specifically measures the level of ultraviolet (UV) radiation from the sun at a particular time and place. This index is crucial for helping people understand the potential for harm from sun exposure, as increased UV radiation can lead to skin damage, sunburn, and other health risks. The index provides a scale that indicates the strength of UV radiation, typically ranging from low to extreme, guiding individuals on how to protect themselves based on the current UV exposure level. It's an important tool for anyone spending time outdoors, especially in regions with high sun exposure.

In contrast, air quality measures various pollutants in the atmosphere, while the temperature of the sun's surface and the amount of visible light are different factors that do not relate to UV radiation exposure specifically. Thus, the focus of the UV Index is purely on UV radiation levels and their potential effects on health.