January Worst air
59/100- Temperature
- 20 / 14°C (68 / 57°F)
- Rain days
- 8
- Crowds
- Busy
The coldest month, at around 20°C by day and 14°C at night, and the one with the worst air of the year. Dry, but grey more often than sunny. Bring a jacket.
Hanoi month scores
25/100
Off-seasonSummer monsoon rainsUrban flooding
August remains hot and wet, with potential for typhoons affecting travel; tourist numbers are at their lowest.
SCORE BY MONTH
High °CLow °CRain daysCrowd levelAQI
Hanoi month by month
Unlike most of the region, the temperature here changes a lot through the year.
February
58/100- Temperature
- 21 / 16°C (70 / 61°F)
- Rain days
- 11
- Crowds
- Peak
Cool, damp and often grey, with drizzle that is closer to mist than rain. Tet usually falls in this month or late January. Air quality is still poor.
March
65/100- Temperature
- 24 / 19°C (75 / 66°F)
- Rain days
- 14
- Crowds
- Busy
Warming up to around 24°C, but humid at over 80%. This is the damp spring period, when moisture condenses on floors and walls. The air starts to improve.
April
54/100- Temperature
- 28 / 22°C (82 / 72°F)
- Rain days
- 13
- Crowds
- Busy
Highs near 28°C and much cleaner air than in winter, but 13 rainy days and high humidity. Comfortable for walking on a dry day.
May
31/100- Temperature
- 32 / 25°C (90 / 77°F)
- Rain days
- 15
- Crowds
- Quiet
Hot, at around 32°C, with the summer rains starting. Storms arrive in the late afternoon.
June
31/100- Temperature
- 34 / 27°C (93 / 81°F)
- Rain days
- 16
- Crowds
- Quiet
Hot and wet. Highs of 34°C, nights that stay at 27°C, and rain on more than half the days.
July
24/100- Temperature
- 34 / 27°C (93 / 81°F)
- Rain days
- 18
- Crowds
- Quiet
The hottest and wettest month, with rain on around 18 days and streets that flood after the heavier storms.
August
25/100- Temperature
- 33 / 26°C (91 / 79°F)
- Rain days
- 17
- Crowds
- Quiet
Much like July: hot, humid and stormy, with flooding possible. Hotel rates are at their lowest.
September
34/100- Temperature
- 32 / 25°C (90 / 77°F)
- Rain days
- 14
- Crowds
- Moderate
Heat falls back to around 32°C, rain eases, and the last summer storms become less frequent. Late September is the better half.
October Best month
67/100- Temperature
- 29 / 22°C (84 / 72°F)
- Rain days
- 10
- Crowds
- Busy
One of the two best months. Warm at 29°C, dry, with clear light and low humidity. Reliable weather for day trips to Ha Long Bay or Ninh Binh.
November
79/100- Temperature
- 25 / 19°C (77 / 66°F)
- Rain days
- 7
- Crowds
- Busy
The other best month, and cooler. Highs of 25°C, only seven rainy days, and comfortable evenings. Air quality starts to worsen late in the month.
December
69/100- Temperature
- 22 / 15°C (72 / 59°F)
- Rain days
- 6
- Crowds
- Moderate
Dry and cool, at around 22°C, with the fewest rainy days of the year. The grey skies and the bad air both come back.
Hanoi weather by month: the four seasons
Hanoi is far enough north to get real seasons. Winter highs are around 20°C and summer highs reach 34°C, a range you will not find in Da Nang or Ho Chi Minh City.
Winter, December to February. Cool and dry, often grey, with drizzle rather than rain.
Spring, March and April. Warmer and more humid than autumn, with mist common in March and rain on 13 to 14 days a month.
Summer, May to September. Hot, humid and stormy, with the heaviest rain of the year from June to August.
Autumn, October and November. Dry, warm and clear, and the best two months of the year.
Hanoi in December and the winter months
December is dry, with the fewest rainy days of the year, and cool at around 22°C.
January and February are colder, at 20 to 21°C, and more humid. It can feel cold because homes and hotels rarely have heating, so a cheap room in January is unpleasant.
Air quality is the real winter problem. From December to February the air over Hanoi is at its worst, and there are days when haze covers the city and the sky never clears. If anyone in your group has asthma, check the reading before planning a long day outside. The Hanoi guide shows the current level.
Hanoi rainy season
The rainy season is May to September, and June, July and August are the worst of it. Rain falls on 16 to 18 days a month and usually arrives as an afternoon or evening storm.
Storms can be heavy enough to flood streets, especially from July to September. The Old Quarter drains slowly, and flooding slows the traffic. Water clears within a few hours.
Summer is also the cheapest time to stay. If you came for the food and the museums, the rain matters less. If you came for Ha Long Bay, it matters a lot.
Tet in Hanoi
Tet is the Vietnamese new year and the biggest holiday of the year. It falls in late January or February and the date moves. The Vietnam guide lists the upcoming dates.
Many small restaurants and shops close for several days, and Hanoi empties as people travel to their home towns. Trains, buses and domestic flights sell out weeks ahead and cost more.
Go then if you want to see the city at its most festive and you accept that many of the places you planned to eat are closed. Avoid it if you need shops and transport to work normally.
Day trips from Hanoi: when to go where
Hanoi is the base for three big trips, and they have different best seasons.
- Ha Long Bay October to December, and March to April The same autumn window as Hanoi, for the same reasons: clear air and calm water. July to September is the main typhoon period on this coast, and cruises can be canceled.
- Ninh Binh Late May to June, and October to November The rice in the Tam Coc valley turns gold in late May and June, which is the reason to time a trip. Autumn is drier and cooler for cycling.
- Sapa September to October, and March to May Much cooler than Hanoi and often inside a cloud. The terraces are green from June and turn golden from September into early October. Winter is cold and the summer months are the wettest.
Planning a trip?
Sign up for our guide.
Frequently Asked Questions
-
What is the best month to visit Hanoi?
October. It is dry, warm at about 29°C, and the humidity has eased. November is a close second and a little cooler. Both are far more comfortable than summer and have better air than winter.
-
Is Hanoi cold in winter?
Cold for the tropics, not cold in absolute terms. December to February highs are 20 to 22°C and lows can reach 14°C. Heating is rare, so indoors often feels colder than outdoors. A warm layer and a jacket are enough.
-
When is the rainy season in Hanoi?
May to September. June, July and August are the wettest, with rain on 16 to 18 days a month. It normally falls as an afternoon storm rather than all day.
-
When is Hanoi cheapest?
June to August. It is the hottest and wettest part of the year, so hotel rates fall. Avoid the week of Tet, when domestic travel pushes prices up.
-
Is air pollution a problem in Hanoi?
In winter, yes. December to February is when the air is at its worst, and there are days bad enough to keep sensitive people indoors. Summer has the cleanest air of the year.