The Department of Disaster Prevention and Mitigation has issued a storm alert for five southwestern and four eastern provinces with warnings of possible flooding and landslides from Friday to Tuesday.
Drector-general Chatchai Phromlert on Friday issued the warning for Krabi, Phangnga, Phuket, Ranong and Trang in the southwest and the eastern coastal provinces of Chanthaburi, Chon Buri, Rayong and Trat.
People living on slopes and in low-lying, waterside and coastal areas were warned to pay special heed.
He said the storms were being generated by the strong southwestern monsoon and a low pressure area over the Gulf of Tonkin.
The Meteorological Department forecast heavy rain from now until Wednesday in areas of the Northeast, the East, the Central Plain and the South. Waves would be 2-3 metres high in the Andaman Sea and the Gulf of Thailand and small boats should remain ashore.