United States UV Index updated daily. Detailed UV forecast charts, with today's ultraviolet radiation in real-time.

Check the accurate UV index today and hourly UV forecast for your location. Protect your skin with real-time, local ultraviolet radiation tracking.

Jul 16, 2025 · Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted by the sun and artificial sources, such as tanning beds. While it has some benefits for people, including the creation …

UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, …

UV Index Today provides national and local UV index forecasts for 40,000+ cities in the United States. Our forecasts include the real-time UV index, the hourly UV index, and the UV Index forecast for the …

The UV Index at any given time is presented as a number ranging from 0 to 14, representing values on a linear scale. A UV Index value of 0 means that there is no UV radiation, and a UV Index of 10 is …

The UV index is a measure to help you determine the effects of the sun on outdoor activities. It is computed using forecast ozone levels, cloudiness, and elevation.

UV rays are strongest in areas close to the equator. Because the sun is directly over the equator, UV rays only travel a short distance through the atmosphere to reach these areas.

Apr 24, 2026 · Ultraviolet (UV) radiation is undetectable by the human eye, although, when it falls on certain materials, it may cause them to fluoresce —i.e., emit electromagnetic radiation of lower …

Unprotected exposure to the sun's ultraviolet (UV) rays can cause damage to the skin, eyes, and immune system.