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UV Index

Tip: If your ZIP code is not found, try searching for your city and state. Some ZIP Codes may not be in our database.

To install the widget on your page: https://www.epa.gov/developers/data-data-products-envirofacts-uv-index-widget.

The UV Index provides a forecast of the expected risk of overexposure to UV radiation from the sun. The National Weather Service calculates the UV Index forecast for most ZIP codes across the U.S., and EPA publishes this information. The UV Index is accompanied by recommendations for sun protection and is a useful tool for planning sun-safe outdoor activities.
 
Ozone depletion, as well as seasonal and weather variations, cause different amounts of UV radiation to reach the Earth at any given time. Taking these factors into account, the UV Index predicts the level of solar UV radiation and  indicates the risk of overexposure on a scale from 0 (low) to 11 or more (extremely high). A special UV Alert may be issued for a particular area, if the UV Index is forecasted to be higher than normal.
 

How is the UV Index calculated?

How do you read the UV Index scale?

How does UV radiation affect your health?

What factors affect the level of UV radiation?

UV Index Forecast

The forecast map shows contour lines of predicted UV Index values during the solar noon hour. The map is created daily from National Weather Service forecast data. Click the buttons for Day 2, Day 3, or Day 4 to see the UV Index forecast for following days. You may notice a brief delay as each map loads. (To find the time of solar noon at your location, use the sunrise-sunset-solar noon calculator at the NOAA website.)

  • Day 1
  • Day 2
  • Day 3
  • Day 4
UV Index forecast map
UV Index forecast map
UV Index forecast map
UV Index forecast map

UV Index Forecast for US Cities

The map below shows predicted UV Index values during the solar noon hour for about 50 U.S. cities. It is created daily by the National Weather Service.

city map of UV indices

UV Index Resources
  • Download the free UV Index smartphone app  
  • UV Alert map - Areas in the U.S. where the UV Index is forecasted to be above normal. (National Weather Service)
  • Cities forecast bulletin - A plain text listing of forecasted UV Index values for 58 U.S. cities. (National Weather Service)
  • Information about the UV Index - (National Weather Service)
UV Index Archives

National Weather Service provides the following UV Index archives: 

  • Monthly averages of the UV Index in the U.S.
  • Graphs of yearly values for select cities
  • Other UV Index data
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on May 27, 2022
United States Environmental Protection Agency

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