Thailand
18 May 2026 - 24 May 2026The rather strong southwest monsoon prevailed over upper Andaman Sea and Thailand in the first half of the week after that weakened. In addition, the low-pressure cell covered lower northern and upper northeastern regions of Thailand in the first half of the week and covered upper Vietnam for few days. These conditions caused abundant rainfall in the first half of the week, particularly in the northern and northeastern regions with flash flood and landslide in some areas. For the southern region, rainfall was observed entire week, especially along the west coast that experienced heavy to very heavy in several areas in several areas in the first half of the week with flooding in some areas.
Region Weather Summary
18 May 2026 - 24 May 2026Northern
Scattered rain with heavy rainfall in some areas except for fairly widespread rain in the middle of the week with heavy to very heavy rainfall in some areas. Gusty wind was reported in Mae Hong Son province on 18 May, Phetchabun province on 19 May and Lampang province on 21 May. Flash flood was reported in Tak and Mae Hong Son provinces during 18-19 May, Phrae province on 19 May, Phetchabun province during 19-21 May, Phitsanulok and Uttaradit provinces on 20 May, Lampang province on 21 May, in addition to, flooding was reported in Nan province on 21 May. Landslide was reported in Mae Hong Son province during 18-19 May and Phetchabun province on 20 May.
| Max Rain | Max. Temp. | Min. Temp. |
| 175.0 mm at Ban Khok Uttaradit on 21 May |
Northeastern
Fairly widespread rain in the first half of the week then decreasing in rainfall to isolated to scattered rain with heavy rainfall in some areas almost the week and very heavy rainfall in several areas at the beginning of the week. Gusty wind were reported in Yasothon province on 18 May. Flooding was reported in Chaiyaphum and Khon Kaen provinces on 18 May and Nakhon Ratchasima province during 18-19 and 24 May.
| Max Rain | Max. Temp. | Min. Temp. |
| 146.0 mm at Mueang Nong Bua Lam Phu Nong Bua Lam Phu on 20 May |
Central
Scattered to fairly widespread rain with heavy rainfall in some areas at the beginning and the middle of the week and very heavy rainfall in some areas on 19 May then decreasing in rainfall to isolated rain. Flash flood was reported in Saraburi province on 20 May.
| Max Rain | Max. Temp. | Min. Temp. |
| 106.4 mm at Khok Samrong Lop Buri on 19 May |
Eastern
Isolated to scattered rain except for fairly widespread rain on 18 and 22 May with heavy rainfall in some areas mainly in the first half of the week and very heavy rainfall in some areas on 18 May. Flooding was reported in Chon Buri province on 20 May.
| Max Rain | Max. Temp. | Min. Temp. |
| 141.4 mm at Mueang Chanthaburi Chanthaburi on 18 May |
Southern (East Coast)
Isolated to scattered rain except for fairly widespread rain during 19-21 May with heavy rainfall in some areas almost the week. Gusty wind was reported in Phatthalung province on 18 May.
| Max Rain | Max. Temp. | Min. Temp. |
| 78.0 mm at Waeng Narathiwat on 22 May |
Southern (West Coast)
Fairly widespread rain almost the week with heavy rainfall in some areas throughout the week and very heavy rainfall in some areas during 19 and 20 May. Gusty wind was reported in Krabi and Phang-nga provinces 19 May and Phuket province on 20 May. Flooding was reported in Phuket province during 18-20 May, Phang-nga province on 19 May and Krabi province on 24 May.
| Max Rain | Max. Temp. | Min. Temp. |
| 168.0 mm at Takua Pa Phang-nga on 20 May |
Bangkok Metropolitan
Scattered to fairly widespread almost the week with heavy rainfall in some areas on 20, 22 and 24 May. Flooding was reported in Bangkok Metropolis on 20 May.
| Max Rain | Max. Temp. | Min. Temp. |
| 71.9 mm at Triamudomsuksanomklao School Khet Saphan Sung on 20 May (49.9 mm at Bang Len Nakhon Pathom on 22 May) |
Announcement Date 25 May 2026 11:52