Is Hanoi worth visiting in December? Yes, but watch the air

Travelers who were there give two answers that look like opposites. On r/VietNam in late November 2025, a Canadian in Hanoi said the mornings had started at 13 degrees and reached 23 to 25 during the day, with no humidity, and that he rode around in a T-shirt or vest while most locals wore jackets. A commenter in another thread, writing in late 2023 about a January visit, said it was under 10 degrees every morning with gusty wind, and he needed heating. Both are true. They are different months, and the difference is what the rest of this page measures.

Why we'd still go

December is the dry month of Hanoi's winter. These are the Hà Nội station's long-term averages from Vietnam's building climate standard, QCVN 02:2022/BXD:

December's 20.2 mm is about 1% of the year's 1,670 mm. It has the fewest rain days of the four months, and almost no drizzle, which is what makes January and February feel damp even when the rainfall total is just as low. The cold comes with the dry: the average low of 15.8°C is a jumper evening, not a coat one. If you can choose, December beats January and February on rain, rain days, drizzle and sun; fog is the exception, and January is about 2°C cooler by day. One caution: the same standard has a second Hanoi station, Hà Đông, and it does not agree on rain: 36.9 mm in December against 28.2 in January. So "driest month" holds at the central station; across the city, read it simply as dry.

Sunshine is the thing in short supply. 113 hours across 31 days is about 3.6 hours a day, and that's the average. The bright run of the autumn is over: November has 131.6 hours, about 4.4 a day, and January drops to 68.7, about 2.2. A December with no rain can still be a month of low cloud. The photo above is a clear day; the one at the top of the page is a grey afternoon on 31 December 2021.

Reddit voices say December is the good month. One r/VietNam commenter answering a 2024 thread said late November to mid-December is "such a wonderful period" and that the morning markets are more beautiful, with steam rising from the hot dishes being sold. In October 2026 another wrote that December will be one of the driest seasons in the north, "especially cities on flat delta like Hanoi", and that Ninh Binh is wonderful in December if you hate tropical heat. That matches the table above.

This December should be a little warmer than usual, and still on the dry side. The national forecast centre's seasonal bulletin of 15 October 2026 gives a 96% probability that a very strong El Niño continues. For December 2026 and January 2027 it expects average temperatures 0.5 to 1.5°C above normal, cold air that is weaker than usual, and cold snaps arriving later and in shorter bursts, though it says strong short spells remain possible. For the Hà Đông station in Hanoi it forecasts a December mean of 19 to 20°C and 20 to 40 mm of rain. The same station averages 18.0°C and 36.9 mm in the standard, so the forecast is about 1 to 2°C warmer, with rain from about half the standard's average to a little above it. For the north as a whole it expects December rain 10 to 20 mm above normal, so a wet week isn't ruled out; we can't reconcile that with the Hà Đông range, because the bulletin's "normal" is its own long-term average.

The sights run to the same hours all winter. The Temple of Literature is open 08:00 to 17:00 every day at 70,000 VND for adults, with an evening programme on Wednesday, Saturday and Sunday that has its own ticket and runs to 22:00. Its English page says the evening starts at 18:00 and its Vietnamese page says 18:30, so check before you plan dinner around it. The Imperial Citadel of Thang Long is open 08:00 to 17:00 every day at 100,000 VND since 1 January 2025. Hoa Lo Prison is open 08:00 to 17:00 every day, including festivals and holidays. The three sit within about 1.2 km of each other, so a grey afternoon can be spent in all three on foot: see the pages for the Temple of Literature, the Imperial Citadel and Hoa Lo Prison.

The catch: the air

This is where we'd be straight with you. On r/VietNam, a commenter in October 2026 said that pollution is "the main issue in Dec", while the weather itself is cool and dry. Another, in a 2023 thread, said the locals feel the cold so much that some burn charcoal briquettes, which makes the already bad air worse. On 3 December 2025 a third answered a thread about Hanoi in late December with five words: "N95 Masks. The good kind."

December has measured numbers, and they are bad. VnExpress International reported on 11 December 2025 that Hanoi woke up to its most severe pollution episode of the winter: the monitor at the Hanoi University of Science and Technology hit an AQI of 227, the third straight day at that level, and IQAir listed the city at 243 at 8:30 a.m., according to the report. Three days earlier VnExpress wrote that on the morning of 3 December the stations in Tay Ho, Gia Lam and Ha Dong all recorded AQI above 200, and that the index stayed there on 6 December. January and February 2026 were no better. On 9 January VnExpress reported that the monitor on Giai Phong Street read an AQI of 228, "very unhealthy", and tied the build-up to a temperature inversion once the cold air steadied. On 4 February the same station read 232 under dense fog, and police suspended traffic on several expressway sections toward Ninh Binh and Thanh Hoa, the first time they had done so for weather. The city's environment department says these winter and spring pollution episodes develop quickly.

Our reading, from a few dated reports and not a count of days: the bad stretches arrive in the still part of winter, and in 2025 the worst of them so far, up to that date, fell on 11 December. We'd treat the air as a daily check, not a reason to cancel. Look at the AQI before you leave the hotel. Put the Temple of Literature, the Citadel and the museums on the bad mornings, and the lake walk, the Old Quarter food streets and the day trips on the clear ones. If you have asthma or travel with small children, pack a mask that fits.

Who should skip it, and what to do instead

Anyone who needs sunshine. With so little sun, December is a month for city walking, not for views. If the plan is Ha Long Bay, one r/VietNam commenter was blunt: you can't swim on the beach or in the sea, and a cold wind can leave a cruise ship in the middle of the sea. Read our Ha Long Bay winter weather post before you book a boat.

Anyone coming from Hoi An or Ho Chi Minh City expecting the same T-shirt weather. North and south are different countries in winter; our north versus south comparison has the numbers. A visitor who was in Hanoi on the 1st to the 5th of December 2022 reported it never got lower than 82 on the first four days, then 77 once a cool change came through on the 5th (Fahrenheit, going by the figures), so early December can still feel warm. Late December is when the layers earn their place. On 1 December 2025 one commenter wrote that lots of foreigners were wearing T-shirts and shorts even at night when it's 15 C, while another reminded the thread that typical Hanoi buildings have no central heating and the rain and wind can make it feel colder.

Anyone headed to Sa Pa too. Hanoi is the mild end of the northern winter; the mountains are not. See Sa Pa in winter before you pack one bag for both.

Anyone packing a full rain kit. You mostly don't need it. One r/VietNam traveler, writing on 1 December 2025 just after two weeks in and around Hanoi, said they got lucky and it only rained once, and that they were shocked at how pleasant it was, coming from a hot and humid country. Our table says to expect about five rain days in December, so a light poncho is plenty.

Our take, by traveler

Walkers, eaters and temple-goers: go in December, and put your big outdoor days on the mornings the air is clear. We'd pick December over January or February because it has about half the rain days of January, a sixth of the drizzle days and 44 more hours of sun. We'd pick late November over December if the dates are yours, since it averages 3.6°C warmer, at the price of more rain (66.7 mm against 20.2). Photographers: the steam over the morning markets is the reason to come. People with asthma, heart disease or small children: December can still work, but plan more of the days indoors and watch the forecast. For what to pack and where else to be in December, our Vietnam in December guide covers the whole country.

A middle path on clothes, from the 2023 thread above: heavier jackets come out in late January or February, and in that commenter's view December is cooler but not cold as such. Bring a sweater and a light jacket that packs small, not a down coat.

How we checked this

Temperatures, rain, sunshine and fog are the Hà Nội and Hà Đông station rows in QCVN 02:2022/BXD, read from the government PDF on 9 November 2026; the percentages and per-day figures are our arithmetic. The 2026 outlook is the national forecast centre's bulletin of 15 October 2026. Sight hours and fees were read from each site's own page on 9 November 2026. The Reddit comments were read one thread at a time in a browser, and their dates are the posting dates.

What we could not confirm

• Whether the Hà Nội station averages cover the same years as the forecast centre's "normal". The standard doesn't state its observation period, and the bulletin compares with its own long-term average, so the 0.5 to 1.5°C above normal can't be added to our table.
• How many December days exceed "unhealthy". We found dated readings for 3, 6, 8 and 11 December 2025, but no monthly count from the ministry or the city, and nothing yet for December 2026.
• Whether a weaker cold-air winter makes the air better or worse. The bulletin says nothing about pollution, and we found no source that links the two.
• When this winter's first cold snap will arrive, or how hard it will hit. The bulletin says cold spells may come later and be short, not when.
• Whether the sunshine figures are right. They come from one source, the standard, and we found no second series to cross-check them.

Photo (cover): Ltn12345 / Wikimedia Commons, CC BY-SA 4.0