The Environmental Protection Department has rated water quality at 19 beaches 'good' and 14 'fair' for this weekend.

Compared with last week, Clear Water Bay First, Kwun Yam and Silverstrand Beaches have been downgraded from 'good' to 'fair'.

Chung Hom Kok and Middle Bay Beaches have been upgraded from 'fair' to 'good', with Kadoorie Beach rising from 'poor' to 'fair'.

Seven gazetted beaches - Anglers', Approach, Ting Kau, Casam, Gemini, Hoi Mei Wan and Lido - are closed to swimmers year round due to poor water quality.

Many beaches are likely to be more polluted than their grades suggest during and after periods of heavy rain. Bathers should avoid swimming at beaches for up to three days after a storm or heavy rainfall.