Sunlight is essential for health, but it also carries its risks. The UV Index identifies the strength of the ultraviolet (UV) radiation from the sun.  It was designed to help you make informed decisions about how much time you should spend in the sun at a particular place, on a particular day, and what protection you should use to help reduce the impact of UV on your health.

It tells you how strong the sun’s UV rays will be. The higher the UV Index, the greater the strength of the sun’s UV rays and the faster you may burn.

The index predicts the risk of UV overexposure on a scale of 0 (minimal risk) to 11+ (very high risk). The forecast considers latitude, elevation, weather conditions, time of year and the ozone levels in your region. The index is based on a type 2 skin type (fair skin, burns easily, tans minimally)

The Solar UV Index is a system developed by the World Health Organisation and looks at the effects of:

• the position of the sun in the sky;
• forecast cloud cover;
• ozone amounts in the stratosphere.

Forecasters gather all this information and input it into an easy to understand index from 1 to 11+, which determines your level of exposure to ultraviolet radiation.

The highest UV index in the UK is approximately 8.

The aim of the index is to warn people of increased risk and encourage them change their behaviour in order to protect themselves against the risks of skin cancer and skin damage.