What is the UV index?

The UV index, also known as the Ultraviolet Index, is an international system of measuring ultraviolet solar radiation for a specific day and geographical location. The higher the index, the more intense and dangerous to your health the solar radiation is.
When the UV Index reaches 3 or more – even on cloudy days – wearing sunglasses is vital, especially for children.
In the UK the Met Office daily UV forecasts include the effects of:
  • the position of the sun in the sky
  • forecast cloud cover
  • ozone amounts in the stratosphere
UV index
Index Exposure
  • 1-2 Low
  • 3-5 Moderate
  • 6-7 High
  • 8-10 Very high
  • 11 Extreme
The UV index does not exceed 8 in the UK and will reach a peak or 7 – 8 in late June around the time of the summer solstice. Indices of 9 and 10 are common in the Mediterranean area.
It’s worth remembering that our eyes are ten times more sensitive to UV light than our skin and children’s eyes are at the greatest risk of UV damage, so protection from UV by wearing good quality (UV400 rated) sunglasses when outdoors in the summer is essential to avoid long term eye damage from UVR.