Rainfall typically begins to lessen in September, though showers remain common and humidity is still high. The countryside stays lush and waterfalls are at their most impressive.
Average daily low and high (°C) and monthly rainfall. The badge shows how it feels, allowing for humidity.
Average temperature across Laos in September.
Luang Prabang, Phongsaly, Oudomxay
September is often the wettest month, with persistent rain keeping river levels high and access to some mountain hamlets limited after storms. Forests remain thick and trekking becomes a wetter, more rugged experience - worthwhile if you don’t mind mud and fewer fellow hikers. Bring a sturdy raincoat, seal electronics in dry bags, and check local conditions frequently before attempting long drives over mountain passes.
Phonsavan
September is often the wettest month on the plateau, with frequent heavy downpours that leave the landscape intensely green and the soil soft. Fieldwork by farmers dominates the local rhythm, and access to isolated jars can be limited after storms; guided tours focus on the main clusters and museum displays in Phonsavan. Travel insurance and contingency days are sensible here if you depend on fixed connections.
Vientiane, Vang Vieng, the Mekong plain
September is typically the wettest month in the central plain, with heavy rains that can lead to temporary flooding in low areas along the Mekong-this affects rural road links and some riverfront access points. Cultural and market life carry on but expect canceled or delayed crossings to river islands after heavy storms. If you plan multi-leg overland travel, leave buffer days and confirm services with local providers.
Pakse, Tad Fane, coffee country
September is often the heart of the wet season, with persistent rain that may disrupt access to some remote coffee farms and waterfalls after very heavy spells. That said, internal roads usually remain passable by sturdy vehicles and the dramatic waterfalls are at their fullest-a photographer’s delight. Flexible plans and local guidance are key if you need to reach off-the-beaten-path villages.
Si Phan Don, Khong, Don Det/Don Khon
September often records the season’s heaviest rains; the Mekong is high and swift, making some rapids impassable and limiting smaller boat travel between islets. The islands are very quiet for tourism, and many businesses run reduced hours-good for travelers who want a near-local experience but not for those needing consistent transport. Flexible plans and local advice are strongly recommended.
There are no major festivals or events in Laos during September to be aware of.
See how September compares with the rest of the year, then read the full guide.