Hanoi Weather by Month: Cold Grey Winter, Hot Wet Summer and the Months in Between

What is the weather in Hanoi, in one minute?

Hanoi does not behave like the rest of Vietnam. Most of the country is warm all year, but the north has a real winter, and a hot, wet summer on the other side of it. Here is the year:

Hanoi: Average high and low temperature, °C

Hanoi: Rainfall, mm

Averages 2015-2025 · Source: Open-Meteo, CHIRPS · How we measure

Read the temperature band first: it drops to 21° in December and January and tops out at 33° in June. Then the rain line: very little rain from November to March, then a big hump from May to September that peaks at 392 mm in August. For one month at a glance, the Hanoi destination page is quicker.

Where to be next: your month-by-month route, $19

A route for your months with a leave-by date for each stop, a backup, and the seasonal traps on your path. Drafted from 11 years of weather data, every number checked against it, in your inbox within 48 hours. Not included: visas, insurance or bookings.

See a sample plan Get my plan, $19

How cold and grey is Hanoi in winter?

December to February: highs of 21° to 22°, nights of 14° to 15°, and a sky that is about three quarters cloud (68 percent in December, 77 in February). Rain is small, 20 to 31 mm a month, so the problem is grey, not wet. Humidity stays above 70 percent, so the cold feels damp.

A fine drizzle does not count as a rainy day in our numbers, so a "dry" month can still mean low cloud and wet streets, which is what people mean by the Hanoi winter. Most flats and many cafes have no heating, so you wear a jumper indoors too. If you like cool walking weather and coffee, it is fine; if you came for sun, it is the wrong city.

When is Hanoi pleasant?

October and November, then March and April in a limited way. November is the best month on paper: a 26° high, a 19° low, 45 mm of rain and the clearest sky of the year (59 percent cloud). October has a 28° high but is still drying out from the rains, with 185 mm.

March and April are warmer (26° and 29°) but cloudy (79 and 69 percent), and the rain climbs from 51 to 91 mm. They are tolerable, not a peak. The window that fits a long stay is October into early December, before the cold grey settles.

How bad is the hot, wet summer?

May to September is the part of Hanoi that visitors rarely plan for. Highs are 31° to 33°, nights stay at 25° to 27°, humidity is 80 to 85 percent and rain runs from 211 mm in May to 392 mm in August, on 16 to 18 days a month in July and August. The rain comes in heavy bursts, streets flood in the worst weeks and an afternoon shower can cancel a motorbike plan. Hot does not mean sunny either: cloud covers 74 to 86 percent of the sky.

With air conditioning it is liveable and rent is low, but there is no month in this stretch we would pick for comfort.

What about the air?

Weather and air are different questions in Hanoi. The cool months are also the ones where official reports say the air is worst, and Hanoi is never really clean at any time of year. The Hanoi air quality guide has the monthly figures for the last three years and which Vietnamese places read lower for the same months. For a winter plan, read the two pages together: December to February is cold, grey and in the higher part of the air range, which is the combination that makes people cancel.

Where should you go instead from December to February?

For northern culture without the winter, go in the shoulder months, October to November. For warmth, go south, but pick with care:

Ho Chi Minh City is the dry, warm answer, as Vietnam in January shows. Da Nang is warmer than Hanoi all winter, but December is still wet there (see Da Nang in December) and January still has about 100 mm of rain, so it only wins clearly in February.

One date for a winter stay: Tet, the lunar new year, falls on 6 February 2027, with an official public break of 4 to 10 February (VnExpress). Many restaurants, gyms and shops close for a week or more and transport is full, so book early or plan to be elsewhere.

Who should come when?

Come in October or November for a month that is easy: warm days, cool evenings and little rain by November. Come in March or April if you accept clouds and the odd wet spell. Treat December to February as a deliberate choice for people who like the cold, and go south for the sun. Skip June to September for a first long stay unless cheap rent matters more than comfort.

This is a weather view only. It does not cover flights, the cost of living or internet quality, so check those before booking.