Ultraviolet (UV) radiation from the sun can have both positive and negative effects on human health.
A small amount of UV radiation is essential in the production of vitamin D, however too much exposure to the sun can have serious effects on your skin and eyes. It is important not to be caught out by the sun so use our forecast to plan your day, keep covered and wear a hat and sunglasses, spend time in the shade and use a high factor sun cream with good UVA protection to protect yourself.
Don't forget that UV rays from winter sun in alpine regions can be more damaging because UV rays are absorbed from the sun and the diffuse UV rays reflected back from snow cover.
Met Office weather app
Get UV forecasts for UK and worldwide locations on the Met Office weather app. The UV forecast shows the UV index for the next 7 days and an hourly forecast for the next 2 days.
- For iPhone the app is available from the App store.
- For Android the app is available from the Google Play store.
Effects of the sun
Sunburn occurs when your skin is overexposed to UV radiation, usually from the sun's rays but also from sunbeds. Extreme sunburn can be very serious and all sunburn can cause serious ongoing health effects, however most people initially experience mild symptoms, such as hot red skin. Protecting yourself against sunburn is very important as excessive UV radiation directly damages the DNA in your skin cells. Often not all of the sun damage will be fully repaired by the body's defence system, so it will gradually cause skin ageing over the years and may lead to skin cancer.
The majority of skin cancer cases are caused by UV radiation either from the sun or sunbeds. It is one of the most common forms of cancer in the UK, with over 15,400 cases of malignant melanoma (the most serious type of skin cancer) and over 20,000 new cases of non-melanoma skin cancer (the less deadly type of skin cancer) diagnosed each year .
Over the last decade, melanoma skin cancer incidence rates have increased by half (50%) in the UK. Rates in males have increased by almost two-thirds (64%), and rates in females have increased by almost two-fifths (39%).
UV radiation can have both short and long term effects on the condition of our eyes. We often protect ourselves against UV by using sun cream or wearing protective clothing, however, we seldom consider what UV can do to our eyes. UV radiation from the sun or sunbeds can damage the eye's surface tissues as well as the cornea and lens. UV can burn the surface of the eye much like sunburn on skin. To protect your eyes from UV exposure wear good quality UV protective sunglasses.
Long term exposure to UV radiation can be more serious. Exposure to UV is a significant risk factor for cataract development, which is the leading cause of blindness in the world. This is where damage is caused to the retina in the eye, and is usually not reversible. Cataracts appear in most people as they age, to different degrees, so protecting your eyes from sun exposure is important.
Your body produces vitamin D when exposed to UV radiation from the sun. Vitamin D helps to regulate the amount of calcium and phosphate in the body, both are needed to keep bones and teeth healthy.
The amount of time you need to spend in the sun to generate enough vitamin D varies from person to person. People can often generate enough vitamin D by spending just a few minutes in the sun. This means people can take the necessary precautions to protect themselves from burning and reduce their risks of developing skin cancer whilst still enjoying the health benefits from sunlight.
At altitude there is less atmosphere to filter UV rays. Snow reflects around 85% of the sun's UV rays so can cause sunburn to the underside of your chin and your ears in particular. Up to 80% of the sun's UV rays penetrate light clouds, and what gets through can reflect back and forth between the clouds and the snow. So even if it's cloudy it's important to protect yourself.
Effects of UV radiation on the eye
Diffused UV rays reflected off of the snow can mean you are subjecting your eyes to twice as much UV light when participating in winter sports . This is why it is important to wear polarised sunglasses/goggles to reduce the amount of UV light, reflected by the snow, reaching and damaging the eye.