The Environmental Protection Department has rated water quality at 20 beaches 'good' for this weekend, with eight more 'fair' and five 'poor'.

Compared with last week, water quality at Lower Cheung Sha, Pui O and Silverstrand Beaches was downgraded from good to fair. Cafeteria New, Cafeteria Old, Golden, Kadoorie and Silver Mine Bay Beaches changed from fair to poor.

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.