Monthly climate guide
Hạ Long weather in September
September in Hạ Long is typically hot, with average daytime highs around 30°C (86°F) and night-time lows near 25°C (77°F). The month usually brings about 257 mm of rain (very wet) and is often cloudy. Daytime highs are about the same as August and 2°C warmer than October.
What stands out in September
- Rain is above Hạ Long's usual level, by about 67%.
- This is rainy-season territory in Hạ Long: short, heavy downpours are typical.
- Humidity near 84% makes 30°C feel stickier than it sounds.
- There's little difference between day and night (around 5°C).
Avg high
30°C
86°F
Avg low
25°C
77°F
Rainfall
257 mm
very wet
Humidity
84%
relative
Sky
71%
cloud · often cloudy
Hạ Long weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 20°C / 67°F | 12°C / 54°F | 51 mm | 82% | 79% |
| February | 22°C / 71°F | 14°C / 57°F | 27 mm | 82% | 84% |
| March | 24°C / 76°F | 17°C / 63°F | 59 mm | 85% | 85% |
| April | 28°C / 82°F | 21°C / 69°F | 77 mm | 85% | 76% |
| May | 30°C / 86°F | 25°C / 76°F | 162 mm | 86% | 74% |
| June | 31°C / 87°F | 27°C / 80°F | 221 mm | 86% | 83% |
| July | 31°C / 87°F | 27°C / 80°F | 343 mm | 86% | 83% |
| August | 30°C / 87°F | 26°C / 79°F | 391 mm | 86% | 82% |
| September | 30°C / 86°F | 25°C / 77°F | 257 mm | 84% | 71% |
| October | 28°C / 82°F | 22°C / 71°F | 168 mm | 82% | 59% |
| November | 25°C / 77°F | 18°C / 65°F | 57 mm | 83% | 63% |
| December | 21°C / 69°F | 13°C / 55°F | 31 mm | 77% | 70% |
What to pack for September
- Light, breathable clothing (cotton or linen)
- A sun hat and high-SPF sunscreen
- A refillable water bottle
- A compact umbrella or packable rain jacket
- Water-resistant shoes
- Quick-dry fabrics — it feels stickier than the temperature suggests
Is September a good time to visit Hạ Long?
Compare the months in the chart above to find your ideal window.
Best time to visit Hạ Long →Other Vietnam cities in September
Cite or embed this data
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Hạ Long weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/vietnam/ha-long/september
<a href="https://weathercompare.eu/weather/vietnam/ha-long/september">Hạ Long weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/vietnam/ha-long" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Hạ Long weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/vietnam/ha-long/september">Hạ Long weather in September</a> – WeatherCompare</p>
Hạ Long in September: quick answers
Is September a good time to visit Hạ Long?
September is one of the wetter months in Hạ Long, with about 257 mm of rain. You can still go: pack a rain jacket and keep plans flexible.
How warm is Hạ Long in September?
Average highs are about 30°C (86°F) and average lows about 25°C (77°F), based on 10 years of daily data.
Does it rain a lot in Hạ Long in September?
Hạ Long typically gets around 257 mm of rain in September — very wet.
Figures are long-term averages for the area around Hạ Long (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.