Hanoi weather in September
In September, Hanoi has an average high of 31 °C87 °F and an average low of 24 °C75 °F, with about 223 mm8.8 in of precipitation. It is the 5th warmest month of the year and ranks 3rd for precipitation.
How September compares with other months
Compared with August, September is 1.2 °C2.1 °F cooler on average and drier by 99 mm3.9 in. Compared with October, September is 2.9 °C5.3 °F warmer on average and wetter by 99 mm3.9 in. Daylight lasts about 12.2 hours around the middle of the month. Average relative humidity is 85% and the average cloud amount 72%.
Is September a good time to visit Hanoi?
September is not among the most comfortable months by our comfort score: it is hot (average high 31 °C87 °F), it is fairly wet (223 mm8.8 in) and it is humid (85%). The most comfortable months in Hanoi are November–March.
What to wear in September
For Hanoi in September, pack very light, breathable clothing, a sun hat and plenty of water and a good rain jacket or umbrella and quick-drying shoes.
September in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Hanoi | 3187 | 2475 | 2238.8 |
| Thanh Xuân | 3187 | 2475 | 2238.8 |
| Gia Lâm | 3187 | 2475 | 2329.1 |
| Bắc Ninh | 3187 | 2475 | 2329.1 |
| Bắc Giang | 3188 | 2374 | 2027.9 |
| Hải Dương | 3187 | 2475 | 2329.1 |
| Phủ Lý | 3187 | 2475 | 25510 |
| Thái Nguyên | 3188 | 2374 | 2017.9 |
| Nam Định | 3087 | 2576 | 26610 |
Other months in Hanoi
- January21 °C69 °F / 11 °C52 °F
- February24 °C75 °F / 13 °C56 °F
- March27 °C81 °F / 17 °C62 °F
- April31 °C88 °F / 20 °C69 °F
- May32 °C90 °F / 24 °C75 °F
- June32 °C90 °F / 26 °C78 °F
- July32 °C90 °F / 26 °C78 °F
- August32 °C89 °F / 25 °C77 °F
- September31 °C87 °F / 24 °C75 °F
- October28 °C83 °F / 20 °C69 °F
- November25 °C77 °F / 16 °C61 °F
- December21 °C70 °F / 12 °C53 °F
Frequently asked questions
How warm is Hanoi in September?
In September the average high in Hanoi is 31 °C (87 °F) and the average low is 24 °C (75 °F).
Does it rain a lot in Hanoi in September?
On average about 223 mm (8.8 in) of precipitation falls in September; it ranks 3rd of the 12 months.
Is September the warmest month in Hanoi?
No. The warmest month in Hanoi is June, with an average high of 32 °C (90 °F). The coldest month is January, with an average low of 11 °C (52 °F).
How long is the day in Hanoi in September?
In the middle of September the day in Hanoi lasts about 12.2 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Hanoi in September?
The average relative humidity in September is about 85%. Combined with warm days, it can feel muggy.
How cloudy is Hanoi in September?
On average about 72% of the sky is covered by cloud in September. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 88 m, while Hanoi lies at about 10 m. Temperatures on this page were therefore adjusted by +0.5 °C0.9 °F using the standard lapse rate of 6.5 °C per 1,000 m.