It also forecasts a 20% chance of thunderstorms and advises people to take care of their health in hot weather conditions.
Thunderstorms may occur in the lower Northeast, Central region, and East regions due to moisture-laden winds from the Gulf of Thailand and South China Sea.
Isolated thunderstorms are also expected in the South.
Waves of 1 metre high are forecast in the Gulf and the Andaman Sea. Boats are advised to keep off thunderstorm-prone areas where waves may rise above 1 metre.
Air pollution is forecast at moderate to high levels in the upper North, lower Northeast, East and Central region including Bangkok, where low winds and stagnant air will lead to the accumulation of fine dust particles.