In July 2026, Thailand was dominated by the
southwest monsoon, which prevailed over the Andaman Sea, Thailand and the Gulf
of Thailand, with moderate to rather strong at times. Additionally, the monsoon
trough periodically lay across the northern and upper northeast of Thailand, it
shifted northward to lie over the upper northern, Laos, and upper Vietnam at
times. Moreover, a low-pressure cell covered upper Vietnam for most of the
month. Besides, at the beginning of the month, the tropical storm “MAYSAK
(2610),” which formed over the upper South China Sea, moved across Hainan
Island into the Gulf of Tonkin and made landfall in Quang Ninh, Vietnam, on 5
July. It subsequently moved into Guangxi, China, weakened into a tropical
depression, and dissipated over southern China. These conditions resulted in
rainfall over upper Thailand at times, particularly in the northern, northeastern,
and eastern regions where heavy to very heavy rainfall occurred in many areas in
the beginning and the end of the month, causing flash flooding and landslides
in some areas. In the southern region, the moderate to rather strong southwest
monsoon brought rainfall in many areas, particularly along the west coast.
However, during the middle of the month, rainfall was relatively decreased in both
amount and distribution due to a ridge of high-pressure from the Southern Hemisphere
extended to cover the Andaman Sea, Thailand and the southern Thailand. Monthly
rainfall was above normal in the northern part 5.6 mm (3%), northeastern part
3.1 mm (1%) and eastern part 106.5 mm (37%). It was inversely below normal in
the central part 23.2 mm (14%), southern part (east coast) 6.0 (5%) and southern
part (west coast) 46.3 mm (13%). The average total rainfall over Thailand in this month was 8% higher
than normal. Overall, the average temperature across Thailand was 0.2 ˚C higher
than normal. Further details are as follows:
Announcement Date 31 July 2026 15:48