Heavy rains are expected to cover around 60-80% of areas, the TMD said in its forecast.
Southwesterly winds are to reach up to 15-35km/h, from today through Tuesday (Sept 15), and up to 20-35km/h next Wednesday and Thursday (Sept 16-17)
Waves during the period of wet weather are expected to average two metres high, reaching up to three metres in thundershower areas, the TMD noted.
Temperatures are forecast to range from minimums of 21-24°C up to maximums of 30-32°C with humidity remaining high as clouds move across the region. The readings in Phuket today alone expected to reach 90%.
The TMD also urged people to be aware of possible flash floods, flooding and landslides.
All ships should proceed with caution and keep away from thundershower areas while small boats were urged to keep ashore throughout the period of heavy weather.
Phuket Governor Narong Woonciew late Thursday ordered emergency services on alert to respond to any flash floods. The order came after heavy rains caused flooding in Patong, Cherng Talay and other areas across the island throughout Thursday, with heavy rains causing minor flooding Thursday night.