New character: The latest Weather Family member is aptly named Violet.

The Hong Kong Observatory launched a new service today - an ultraviolet index forecast, to help people take appropriate protective measures against UV radiation when planning outdoor activities.

At 5pm every day, starting from today, a forecast of the maximum UV index for the following day will be provided.

When the UV index is expected to be 11 (corresponding to an extreme UV level) or above, people will be reminded to take protective measures, such as avoiding prolonged exposure to sun.

The UV forecast information can be obtained through radio, television, Dial-a-Weather service (1878 200-313), the Observatory's website and Personal Digital Assistant (PDA) website.

Observatory Assistant Director Dr Lee Boon-ying said the forecast aims to help people, especially those frequently engaged in outdoor activities, to take necessary protections against UV exposure.

Department of Health's Principal Medical & Health Officer Dr Ng Chi-cheung said moderate exposure to the sun is good for people's health, but overexposure to UV could induce skin and eye injuries, including a swelling of the eye known as photokeratoconjunctivitis and cataracts, and skin cancer.

On days when the UV Index is high, people should wear a hat, use an umbrella, wear suitable clothing and apply sunscreen lotion to protect the body, he added.