UV Radiation

On this page:
What is the UV Index? | When to protect your skin from UV | Know your UV | Reflective UV | UV exposure | UV damage

What is the UV Index?

The World Health Organization's Global Solar UV Index measures UV levels on a scale from 0 (Low) to 11+ (Extreme).

The UV level is affected by several factors including the time of day, time of year, cloud cover, altitude, location and surrounding surfaces.

Most parts of Australia have high levels of UV radiation from the sun all year round. UV radiation cannot be seen or felt and is not related to temperature.

How does UV reflect off surfaces?

UV can reflect off different surfaces and be scattered by particles in the air. UV reflects from surfaces, especially if smooth, shiny or light-coloured, and natural surfaces, like sand, water or snow.

Why is UV a risk in the snow?

UV levels can be more intense in the snow for two reasons:

• The atmosphere is thinner at high altitudes and absorbs less UV radiation from the sun. UV radiation intensity increases by about 10–12% for every 1000 metres of altitude.
• Snow is highly reflective. On a sunny day, clean fresh snow can reflect up to 90% of UV radiation. This means you can be exposed to almost a double dose of UV – directly from the sun and bouncing off snow-covered surfaces.