The Meteorological Department reported that as of 5am on Monday tropical storm Kujira in the upper South China Sea was centred about 180 kilometres from Hinan Island, China, with maximum sustained winds of about 75km per hour and moving slowly in a northerly direction.
The storm is likely to cover Hainan Island and the southern part of China by June 24.
This is likely to result in more rain in the eastern part of the Northeast of Thailand from now until June 25.
Travellers going to Hainan Island and Hong Kong are advised to check weather forecasts before departure.
Meanwhile, the southwest monsoon prevailing over the Andaman Sea, the South Region, and the Gulf of Thailand is intensifying. This will result in rain and isolated heavy rain over the East and West coasts as well as the South.
Waves in the Andaman Sea and the upper Gulf of Thailand are still strong. All boats should proceed with caution. Small boats in the Andaman Sea, in particular, should remain ashore during June 22-27.