UV Index
The UV Index is a forecast of the amount of skin damaging UV radiation expected to reach the earth's surface at the time when the sun is highest in the sky (around midday). The amount of UV radiation reaching the surface is primarily related to the elevation of the sun in the sky, the amount of ozone in the stratosphere, and the amounts of cloud cover. However, thick cloud can greatly reduce ultraviolet radiation levels and, surprisingly, certain types of thin cloud can magnify the ultraviolet radiation strength.
The peak daily ultraviolet radiation level changes over the year. The strongest being at the Summer solstice (21st June) and the weakest at the Winter solstice (21st December).
The UV Index can range from 0 (at night) to 11 or 12. It might even be higher in the tropics and/or at high elevations under clear skies. The UV Index does not exceed 8 in the UK (8 is rare; 7 may occur on exceptional days, mostly in the two weeks around the summer solstice). However, indices of 9 and 10 are common in the Mediterranean area.
The higher the UV Index, the greater the dose rate of skin damaging (and eye damaging) UV radiation. Consequently, the higher the UV Index, the smaller the time it takes before skin or eye damage occurs. Find out about your risk and burning time with our skin type table
| Risk of damage to skin | ||||
| UV INDEX | SKIN TYPE | |||
| white (burners) | white (tanners) | naturally brown | naturally black | |
