Hanoi in September: Weather & climate information
- Hanoi's autumn weather showcases cooler temperatures and reduced rainfall, especially in the latter half of the month.
- The climate remains humid, with potential tropical storms.
- September also marks the return to school, leading to increased traffic congestion.
The end of the lengthy rainy season in Hanoi heralds the arrival of its enchanting autumn, a time marked by blossoming flowers and romance. Hanoi's autumn has inspired countless songs and poems, capturing its breathtaking beauty and serene atmosphere. As the leaves change, the city transforms into a picturesque setting that delights both locals and visitors alike.
September Averages
In September, Hanoi experiences warm weather with temperatures ranging from 24.3°C to 31.7°C. Humidity is high at 79.4%, and the city sees about 109.5mm of rain over five rainy days, yet enjoys around 10.8 hours of sunshine daily.| Min Temperature | 24.3°C | Precipitation | 109.5mm |
| Max Temperature | 31.7°C | Rainy Days | 5.0 days |
| Humidity | 79.4% | Sunshine Hours | 10.8 hours |
Historical weather
September weather averages for Hanoi in the last 14 years ( 2010 to 2024).
- 2010
- 2011
- 2012
- 2013
- 2014
- 2015
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|
1 27.0°37.0° | 2 28.0°37.0° | 3 29.0°36.0° | 4 28.0°36.0° | 5 28.0°35.0° | 6 27.0°36.0° | |
7 27.0°29.0° | 8 27.0°29.0° | 9 26.0°33.0° | 10 27.0°34.0° | 11 27.0°35.0° | 12 27.0°32.0° | 13 27.0°33.0° |
14 26.0°33.0° | 15 26.0°33.0° | 16 27.0°33.0° | 17 27.0°34.0° | 18 25.0°30.0° | 19 21.0°26.0° | 20 23.0°25.0° |
21 24.0°30.0° | 22 26.0°30.0° | 23 26.0°32.0° | 24 23.0°31.0° | 25 25.0°31.0° | 26 26.0°33.0° | 27 25.0°32.0° |
28 24.0°31.0° | 29 26.0°33.0° | 30 26.0°33.0° |
Temperature Graph (°C)
The average Hanoi temperature during September is around 27.8°C (82.04°F).
| Month | High | Low | Changes |
| August | 32.8°C (91.04°F) | 25.5°C (77.9°F) | -1.1°C (30.02°F) |
| September* | 31.7°C (89.06°F) | 24.3°C (75.74°F) | -1.1°C (30.02°F) |
| October | 29.3°C (84.74°F) | 21.9°C (71.42°F) | -2.5°C (27.5°F) |
Humidity Graph (%)
The average humidity in September in Hanoi is 79.4%, which is 0.1% lower than August and 6.0% higher than October.
Rainfall Graph (mm)
Average rainfall in September in Hanoi: 109.5mm
| August | September* | October |
| 184.6mm (-75.1mm) | 109.5mm | 77.8mm (+31.7mm) |
Rain Days Graph
Average rain days in September in Hanoi: 5.0 days
Daylight Graph
Average daylight in September in Hanoi: 12.3h
Tips for Visiting Hanoi in September 2025
September marks the transition from summer to autumn in Hanoi, bringing with it cooler and more pleasant weather. While temperatures can still be warm, they are generally more comfortable compared to the extreme heat experienced in June and July, with reduced sunlight.
In September, temperatures typically range between 26 to 31°C (79 to 88°F), with the highest temperatures remaining below 35°C (95°F). The decrease in humidity, coupled with gentle breezes, soft sunlight, and clear blue skies, transforms Hanoi into a picturesque city. Besides packing T-shirts and shorts, visitors should consider bringing a good camera to capture the stunning tree-lined boulevards adorned with milk wood pines, and the streets blanketed with golden leaves.
September also brings the celebration of Vietnam’s Independence Day on September 2nd, with numerous exciting events taking place throughout the city. Shopping centers often host special promotions and entertainment venues typically feature lively activities to honor the holiday.
Another highly anticipated event is the Mid-Autumn Festival, which usually occurs in the second half of September or occasionally extends into early October. During this festive time, the streets of Hanoi are illuminated with vibrant red lanterns and adorned with colorful decorations for children. Moon cakes are a must-try delicacy for those visiting during the festival.
September marks the tail end of the rainy season in Hanoi, so visitors should still prepare for occasional rain showers. Despite this, the beauty of Hanoi's autumn makes it a highly recommended destination during this time.
What to Pack
When planning a trip to Hanoi in September, it’s advisable to pack T-shirts and shorts for the warm days, along with light sweaters for cooler evenings. While sunscreen may not be absolutely necessary, it's recommended for protecting against UV rays during prolonged outdoor activities. Given the lower humidity levels, it's also important to stay hydrated by drinking plenty of water.
