BANGKOK, THAILAND – Thailand’s weather agency warned of ongoing summer storms in northern, northeastern and eastern regions, putting 25 provinces on alert for 21 April.
Final weather warning from the agency
On 20 April, the Thai Meteorological Department (TMD) issued its summer storm warning for Upper Thailand, bulletin No. 13. The notice applied through 21 April 2026 and was described as the “last issue” of this warning series.
According to the statement, residents in 25 provinces faced a risk of thunderstorms, strong gusts, localised hail and isolated lightning strikes. The agency framed the situation as a temporary but potentially dangerous weather phase.
Expected weather hazards
The TMD reported that parts of the North, Northeast and East could continue to experience summer storms, mainly as thunderstorms. Accompanying these storms, strong wind gusts were expected, with hail possible in some local areas.
The statement also warned of lightning strikes in several regions. People in the affected provinces were urged to stay alert to rapidly changing conditions.
Causes: moist air meets intense heat
The weather service cited southerly and southeasterly winds as the main trigger, bringing moist air from the Gulf of Thailand and the South China Sea. This inflow of moisture met widespread hot to very hot conditions over Thailand.
The combination of high heat and humid air was expected to favour thunderstorm development. Authorities indicated that this pattern typically led to short but intense convective storms.
Safety advice for residents and travellers
Officials advised the public to avoid open areas during storms and not to seek shelter under large trees. They also urged people to stay away from unstable buildings and insecure advertising signs that could be toppled by strong winds.
Travellers in the affected regions were asked to pay close attention to local weather updates. Extra caution was recommended for anyone planning outdoor activities on 21 April.
Guidance for farmers and health precautions
Farmers were told to support or secure fruit trees and take preventive measures to limit damage to crops and livestock. The TMD highlighted the risk of losses if preparations were not made before storms hit.
In addition, the public was encouraged to pay particular attention to their health during this period of changeable weather. Authorities pointed to the combination of heat and sudden storms as an added physical strain.
These 25 provinces were affected
In Northern Thailand, the provinces of Nan, Uttaradit, Phitsanulok and Phetchabun were listed. In the Northeast and East, the warning covered Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Sakon Nakhon, Nakhon Phanom, Udon Thani, Mukdahan, Yasothon, Amnat Charoen, Khon Kaen, Chaiyaphum, Nakhon Ratchasima, Buri Ram, Surin, Si Sa Ket and Ubon Ratchathani.
The eastern provinces of Prachin Buri, Sa Kaeo, Chachoengsao, Chanthaburi and Trat were also included. Residents in all named areas were advised to monitor the skies and secure property against sudden storms.
How to stay informed
The TMD urged the public to continue following its official announcements, as thunderstorm situations could change at short notice. People in the affected regions were told to stay updated until the end of the warning period on 21 April 2026.
Information was available via the weather service website (www.tmd.go.th) and around the clock by telephone on 0-2399-4012-13 and 1182. Authorities stressed that timely access to reliable forecasts was key to reducing storm-related risks.