Thailand
17 August 2026 - 23 August 2026The monsoon trough lay across Myanmar, upper northern Thailand and upper Laos extending into a low-pressure cell over upper Vietnam at the beginning of the week. After that, it shifted southward to lie across the northern and upper northeastern regions of Thailand, extending into an active low-pressure cell over the South China Sea and Hainan Island in the middle of the week. The low-pressure cell subsequently intensified into a tropical depression in the afternoon on 21 Aug. and developed into tropical storm “NARRA (2619)” in the morning on 22 Aug. before moving into the Gulf of Tonkin. The monsoon trough shifted northward to lie across upper northern Thailand and upper Laos at the end of the week. Additionally, the rather active southwest monsoon prevailed over the Andaman Sea, Thailand and the Gulf of Thailand almost the week. These conditions brought abundant rainfall in upper Thailand at the beginning and the middle of the week, particularly the northern and northeastern regions resulting in flooding in some areas. In the southern region, rainfall was mainly observed upper part of the region.
Region Weather Summary
17 August 2026 - 23 August 2026Northern
Fairly widespread rain at the beginning and the middle of the week then decreasing in rainfall to scattered rain with heavy to very heavy rainfall in some areas almost the week. Flooding was reported in Chiang Rai province during 17-18 Aug., Mae Hong Son province on 20 Aug., Phayao province during 19-20 Aug., Nan province on 19-23 Aug., Sukhothai and Phitsanulok provinces during 20-23 Aug., Phetchabun provinces during 20-22 Aug. and Uttaradit province during 21-22 Aug. Landslide was reported in Mae Hong Son province on 20 Aug.
| Max Rain | Max. Temp. | Min. Temp. |
| 195.0 mm at Pua Nan on 18 Aug. |
Northeastern
Fairly widespread rain except for isolated to scattered rain on 17 , 22 and 23 Aug. with heavy to very heavy rainfall in some areas during 18-21 Aug. Flooding was reported in Ubon Ratchathani province during 18-23 Aug., Nakhon Phanom province on 20 Aug and Sakon Nakhon during 20-21 Aug.
| Max Rain | Max. Temp. | Min. Temp. |
| 156.1 mm at Phu Phan Highways Division, Phu Phan Sakon Nakhon on 19 Aug. |
Central
Fairly widespread rain except for isolated to scattered rain on 17 and 21 Aug. with heavy rainfall in some areas almost the week and very heavy rainfall in some areas on 19 Aug.
| Max Rain | Max. Temp. | Min. Temp. |
| 187.9 mm at Sahathanakan Krungthep Border Patrol Police School, Sangkhla Buri Kanchanaburi on 19 Aug. |
Eastern
Fairly widespread rain almost the week with heavy rainfall in some areas throughout the week and very heavy rainfall in some areas on 18 Aug.
| Max Rain | Max. Temp. | Min. Temp. |
| 100.8 mm at Khlong Yai Trat on 18 Aug. |
Southern (East Coast)
Scattered to fairly widespread rain except for scattered rain on 17 and 19 Aug. with heavy rainfall in some areas on 18 , 20 and 22 Aug.
| Max Rain | Max. Temp. | Min. Temp. |
| 65.6 mm at Su-ngai Kolok Narathiwat on 22 Aug. |
Southern (West Coast)
Scattered to fairly widespread rain except for isolated rain on 21 and 22 Aug. with heavy rainfall in some areas on 17 , 18 , 20 and 21 Aug. Gusty Wind was reported in Krabi province on 18 Aug.
| Max Rain | Max. Temp. | Min. Temp. |
| 70.4 mm at Mueang Ranong Ranong on 20 Aug. |
Bangkok Metropolitan
Scattered to fairly widespread rain except for isolated rain on 21 Aug. with heavy rainfall in some areas on 17 Aug.
| Max Rain | Max. Temp. | Min. Temp. |
| 32.4 mm at Triamudomsuksanomklao School Khet Saphan Sung on 18 Aug. (37.4 mm at Bang Bo Samut Prakan on 17 Aug.) |
Announcement Date 24 August 2026 11:14