Vietnam
Hanoi in September: weather & travel advice
This month's data profile
Rain shapes the decision
Hanoi in September is climatically mixed. The average daily high is around 30 °C. With about 18 rainy days it is very wet.
Historical monthly averages, not a weather forecast. Individual days and years can differ substantially.
Rank among 12 monthly averages
45/100 · #8
Warmth
#6
Dryness
#8
Sun
#5
Published best categories: none
Hanoi · SeptemberPhoto: Christopher Crouzet · CC BY-SA 4.0Climate facts
- Average high
- 30 °C
- Average low
- 23 °C
- Rainy days (est.)
- 18 rainy days (est.)
- Sun (est.)
- 6 h/day
- Humidity
- 85 %
Climate evidence with direct month comparison
The highlighted row is the selected month. Precipitation total and rainy days are separate monthly averages.
| Month | Avg high °C | Avg low °C | Rainy days (est.) | Precipitation mm | Sun h/day (est.) | Humidity % | Wind m/s | Score |
|---|---|---|---|---|---|---|---|---|
| August | 31 | 25 | 23 | 311 | 5.9 | 86 | 1.4 | 36 |
| September (selected) | 30 | 23 | 18 | 231 | 5.7 | 85 | 1.5 | 45 |
| October | 28 | 20 | 12 | 125 | 4.9 | 83 | 1.7 | 67 |
How do the previous and next months compare?
Baseline: September (45/100)
Positive and negative values show the change from the selected month.
| Score Δ | Average high Δ | Average low Δ | Rainy days Δ | Rain Δ | Sun Δ | Humidity Δ | Wind Δ | |
|---|---|---|---|---|---|---|---|---|
| August | -9 | +0.9 °C | +1.6 °C | +5.1 | +80.1 mm | +0.2 h | +0.8 % | -0.1 m/s |
| October | +22 | -2.5 °C | -3.5 °C | -6.5 | -105.3 mm | -0.8 h | -1.7 % | +0.2 m/s |
All twelve months in context
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Useful next decisions
Frequently asked questions
How warm is Hanoi in September?
The average daily high is around 30 °C, with an average daily low of about 23 °C.
Does it rain a lot in Hanoi in September?
The curated estimate is about 18 rainy days per month, not a directly measured long-term average. Total precipitation averages around 231 mm for the month. A rainy day does not mean all-day rain.
When is the best time to visit Hanoi?
By the climate score, January, February, November and December are the strongest months for Hanoi. September is not among them.