The Solar UV Forecast

Describing levels of solar UVR

Levels of solar UVR vary across the country on any given day.
The UV index is a rating system adopted from the World Health Organisation and provided by the MET Office in the UK.
The forecast is expressed as a 'Solar UV Index' and includes 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 in to the easy to understand index from 1 to 11+, which determines your level of exposure to ultraviolet radiation. The higher the number, the stronger the levels of solar UVR and the less time it takes for damage to occur.

The value of the index ranges from zero upwards. The UV index has five categories:

• Low: UV Index of 1-2
• Moderate: UV index of 3-5
• High: UV index of 6-7
• Very high: UV index of 8-10
• Extreme: UV index of 11 and above

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 damage and skin cancer.
When the UV index is at 3 and above, the amount of solar UV radiation reaching the earth's surface is strong enough to damage the skin, which can lead to skin cancer. It is therefore important to frequently check the UV forecast to ensure that the appropriate precautions are taken and if necessary issue alerts to employees. You can check the UV index at any time and for any location via the homepage on this website or by visiting the Met Office website.

Remember that UVR can penetrate cloud and can be reflected off ground surfaces such as:
water, sand, glass, metal and snow. Click here to view a diagram which explains factors affecting levels of Solar Ultraviolet Radiation >