The Environmental Protection Department has rated water quality at 23 beaches 'good' and 10 'fair' for this weekend.

Compared with last week, Ma Wan Tung Wan Beach has been upgraded from 'poor' to 'fair', and Stanley Main Beach has been changed from 'good' to 'fair'.

Seven gazetted beaches - Anglers', Approach, Ting Kau, Casam, Gemini, Hoi Mei Wan and Lido - 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 heavy rain. Bathers should avoid swimming at beaches for up to three days after a storm or heavy rainfall.