Monthly Weather Summary

In May 2024, hot weather still persisted in Thailand at the beginning and the middle of the month especially in the beginning of the month that scorching hot was observed in many areas of the northern, northeastern and central parts and also in some areas of the eastern part due to the covering of the heat low-pressure cell over upper Thailand at that time. However, the temperature was relatively decreased at the end of the month, relieving the heat. The average temperature in this month was higher than normal nationwide with the average value across the country of 1.3˚C above normal, the maximum temperature set a new highest record in many places. For rainfall, upper Thailand received less rainfall with uneven distribution of rain in the beginning and the middle of the month. At the end of the month, most areas experienced an increase in rainfall brought by the Southwest Monsoon due to the effects of the southwest monsoon that dominated the Andaman Sea, Thailand, and the Gulf of Thailand, the low-pressure cell covered the upper central and lower northern parts and over the Gulf of Tonkin and upper Vietnam for few days. In addition, tropical cyclone "REMAL, (01B)" in the Bay of Bengal made landfall at southern Bangladesh and tropical storm "MALIKSI, (2402)" moving in the central South China Sea which brought successive rain which considered as the start of Thailand’s rainy season on May 20. For the southern part, the influenced of the easterly and southeasterly winds that occasionally blew over the Gulf of Thailand, southern part and the Andaman Sea at the beginning and the middle of the month and the southwest monsoon prevailed over the Andaman Sea. Thailand and the Gulf of Thailand at the end of the month. These causes intermittent rain for almost the whole month mainly on the west coast.  The total rainfall was higher than normal in most parts i.e. northern part 18.4 mm (11%), northeastern 25.4 mm (13%), central part 56.5 mm (34%), eastern part 75.8 mm (37%) and southern part (west coast) 2.6 mm (1%) while it was inversely below normal in the southern part (east coast) 35.0 mm (27%). The average rainfall over the whole areas of Thailand was 12% higher than normal. For more details were as follow.