Thailand’s Department of Disaster Prevention and Mitigation issued a formal travel advisory for northern provinces, citing above-average rainfall forecasts through October 2026. Chiang Mai, Chiang Rai and Mae Hong Son are under the highest alert level.
Flash floods and landslides have already disrupted roads near Pai and Doi Inthanon national parks. Several guesthouses in low-lying areas have been temporarily closed by authorities.
The advisory coincides with the peak of the annual monsoon season, which historically causes the most incidents between mid-July and mid-October.
What this means for you
Check road conditions daily via the department’s app before driving to rural hill-tribe villages. Consider flexible booking options or travel insurance that covers weather disruptions.
Opt for higher-elevation hotels in Chiang Mai city rather than riverside properties if travelling in September. Avoid trekking trails that cross streams during heavy downpours.
Domestic flight cancellations remain rare, but allow extra time for transfers between Bangkok and northern airports.