Ultraviolet Radiation

Ultraviolet Radiation

An Ultraviolet meter is used to tell people how long they can be in the sun without protection at different times throughout the day before sunburn is likely. Each day the intensity of the sun’s UV rays is calculated on a scale of 1-15. The higher the number on the scale, the more intense the UV radiation is, and therefore the more rapidly sun damage to your skin begins. Five categories are used to describe the strength of UV radiation:

Minutes before your skin is damaged
UV Reading Level Fair Skin Medium Skin Dark Skin
0 – 2.9 Minimal 44-120+ 74-120+ 120+
3 – 4.9 Low 26-43 44-71 77-120+
5 – 6.9 Moderate 19-26 31-43 55-76
7 –9.9 High 13-18 22-31 38-54
10+ Very High 9-13 14-21 25-38

On most days the UV radiation reaches its peak intensity at approximately 1 p.m. At this time sun exposure should be limited. The Food and Drug Administration (FDA) and the American Academy of Dermatology recognize six skin categories, listed below.

FDA Skin Type Skin Reaction to the Sun Description Skin Category
I Always burns easily, never tans, extremely sun sensitive Red-headed, freckles, Celtic, Scottish, Irish Light
II Always burns easily, tans minimally, very sun sensitive Fair-skinned, fair-haired, blue-eyed Caucasians Light
III Sometimes burns, tans gradually to light brown, minimally sun sensitive Average skin Medium
IV Burns minimally, always tans to moderate brown, minimally sun sensitive Mediterranean-type Caucasians Medium
V Rarely burns, tans well, skin not sensitive to sun Middle Eastern, some Hispanics and some African-Americans Dark
VI Never Burns, deeply pigmented, skin not sensitive to sun African-Americans Dark

To find out about the ultraviolet reading in your area go to: