With the end of the hot season, the Meteorological Department officially declared Thailand's rainy season beginning 15 May 2026. At the same time, Chiang Mai province issued its first urgent warning to 25 districts to prepare for flash floods, sudden flooding, and waterlogging due to heavy to very heavy rain between 14-18 May 2026.
On 14 May 2026, Chiang Mai province issued an urgent announcement warning 25 districts to prepare for heavy to very heavy rainfall between 14-18 May 2026. This follows the Meteorological Department's forecast that the northern region, including Chiang Mai, will experience heavy to very heavy rain with risks of flash floods, sudden flooding, and waterlogging in many areas.
Mr. Siwakhon Buapong, Deputy Governor of Chiang Mai, instructed all districts and local administrative organizations to closely monitor weather conditions, especially in high-risk areas such as foothills, near water flow paths, and natural tourist sites—particularly waterfalls and streams. If heavy rain persists, authorities should promptly alert residents and tourists, immediately block hazardous areas, and prepare temporary shelters, food, drinking water, and essential supplies to support those affected.