The UV Index
What does the UV index mean?
The levels of UV radiation and therefore the values of the index vary throughout the day. In reporting the UVI, most emphasis is placed on the maximum UV level on a given day. This occurs during the four-hour period around solar noon. Depending on geographical location and whether daylight saving time is applied, solar noon takes place between noon and 2 p.m. The media usually present a forecast of the maximum UV level for the following day.