What is UV Index?
UV Index meaning Ultraviolet Index- This index provides important information to help you plan your outdoor activities in ways that prevent overexposure to the sun’s rays. It was designed by the National Weather Service (NWS) and the Environmental Protection Agency (EPA). Unlike some countries’ indices, the United States UV Index is not based upon surface observations. Rather, it is computed using forecasted ozone levels, a computer model that relates ozone levels to UV incidence on the ground, forecasted cloud amounts, and the elevation of the forecast cities. The calculation starts with measurements of current total ozone amounts for the entire globe, obtained via two satellites operated by the National Oceanic and Atmospheric Administration (NOAA). These data are then used to produce a forecast of ozone levels for the next day at various points around the country.
|Category||UV Index||Time to Burn||Actions to Take|
|Minimal||0 – 2||60 min. +||Apply SPF sunscreen.|
|Low||3 – 4||45 min.||Apply SPF sunscreen, wear a hat.|
|Moderate||5 – 6||30 min.||Apply SPF 15, wear a hat.|
|High||7 – 9||15 – 24 min.||Apply SPF 15 to 30, wear a hat and sunglasses. Limit midday exposure.|
|Very High||10+||10 min.||Apply SPF 30; wear a hat, sunglasses, and protective clothing; limit midday exposure.|
reference: National Weather Service Glossary