September is mixed in terms of weather.

By September the weather has improved in the north with less rain and lower temperature.
It is the best month to visit Sapa and other mountainous regions where you can admire golden rice paddy terraces and fantastic mountain views.
In the south rain gradually becomes less intense, especially towards the end of the month.
It is a different story for central regions however as the wet season starts kicking in this month with rain being more frequent in Hue, Hoi An and Danang.

North Vietnam

September is autumn time in the north with much less rain and more pleasant weather.

Hanoi: By September the rain has lessened down. The sun starts to show up more often, and with milder temperatures you have the near perfect weather to explore the capital.

Ha Long: Rain starts to lessen down from this month and the weather starts getting more pleasant.  

Sapa: Warm, sunny and very pleasant weather with much less rain. It is any photographer’s dream to visit Sapa this month as the region is the most glorious this time of the year with beautiful rice paddy terraces and glorious mountain views.

Mai Chau: Warm, sunny and slightly lower temperature compared to previous months.

Central Vietnam

September is the start of rainy season in central Vietnam. Hue, Danang and Hoi An can experience days of drizzling rain, concrete skies and cool temperatures. Look out for occasional flooding from September to November.

Hue & Hoi An: rainy weather with grey skies. Plan your trip in early September to avoid occasional flooding that usually happens from the end of the month.

Nha Trang: Sunny and very pleasant weather throughout the whole of September with chances of rain at the end of the month.

Da Lat: warm, pleasant weather with occasional rain that usually stops by end of October.  

South Vietnam September marks the tail end of the rainy season in south Vietnam. Rain is much less frequent with the region start transitioning to drier weather. There are more dry daylights hours to enjoy, now with slightly more pleasant weather too.

Ho Chi Minh City:  Hot, sunny weather during the day with much less rain, especially by the end of the month. Evenings and early mornings are cooler with lower humidity.

Mekong Delta: Still hot, humid weather with less rain. September is the start of the flood season in the Mekong when the rice fields are flooded and the fruit orchards are bursting with colour. It is a great time of the year to explore the waterways now that the canals, rivers, channels, wetlands are brim-full.

Phu Quoc: Hot, humid and frequent rain. Ever picture yourself shelter from the summer rain under a palm tree? Now you have the opportunity to do it!

Con Dao: Sunny weather with short, intense rain that lasts over an hour or so which brings much need relief from the heat.