The UV Index is issued daily to advise you on the strength of the sun’s UV rays in your region.  The UV Index is based on monitoring the sun’s position, cloud movements, altitude, ozone data, and other factors.

The rise in skin cancers over the past decades is strongly correlated to the increased popularity of outdoor activities and recreational exposure.  When planning your outdoor activities, be aware of the UV index and try to limit your sun exposure during higher levels.  And remember, UV radiation is present everyday, even when it’s cloudy.

Weather Channel:
http://www.weather.com/maps/activity/skinprotection/currentuvindex_large.html

EPA:
http://www.epa.gov/sunwise/uvindex.html

National Weather Service
http://www.weather.gov/view/national.php?prodtype=ultraviolet

The UV Index