The Environmental Protection Department has rated 11 beaches 'food', 15 'fair' and seven 'poor' this weekend.

Compared with the grading released last week, Kwun Yam Beach and Shek O Beach have been upgraded from 'fair" to 'good', and Silver Mine Bay Beach has been upgraded from 'poor' to 'fair'.

Lower Cheung Sha Beach has been changed from 'good' to 'fair', and Golden Beach and Ma Wan Tung Wan Beach have been changed from 'fair' to 'poor'.

The department said the changes are generally within the normal range of fluctuation of the bacteriological water quality of the beaches

Seven gazetted beaches - Anglers' Beach, Approach Beach, Ting Kau Beach, Casam Beach, Gemini Beaches, Hoi Mei Wan Beach and Lido Beach - are closed to swimmers year round because of 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.