Among those planning a Hanoi trip, some may be wondering, "Which month is the most comfortable to go?" "Should I avoid the hot season?"
Southeast Asia has an image of being "summer all year," but Hanoi, like Japan, has four seasons, and the temperature and rainfall change greatly by season.
本記事では、平年値を旅行計画へ使う方法と、直前予報・大気質・運航情報を組み合わせる手順を解説します。取材記録のない「在住者目線」は根拠にしません。
A must-read for anyone who wants to travel aiming for the best season.
The features of Hanoi's climate and month-by-month weather data
Hanoi's month-by-month weather data
| Month | Average high | Average low | Average rainfall | Travel suitability |
|---|---|---|---|---|
| January | 21℃ | 13℃ | 30mm | x Cold, air pollution |
| February | 21℃ | 16℃ | 20mm | x Cold, air pollution |
| March | 24℃ | 17℃ | 60mm | O More sunny days |
| April | 26℃ | 21℃ | 90mm | O Many days with good weather |
| May | 30℃ | 23℃ | 190mm | △ Rainy season begins, gets hot |
| June | 32℃ | 25℃ | 250mm | x Scorching heat |
| July | 33℃ | 27℃ | 300mm | x Scorching heat |
| August | 34℃ | 26℃ | 330mm | △ Typhoons can come |
| September | 32℃ | 24℃ | 250mm | O Good climate but watch for typhoons |
| October | 29℃ | 21℃ | 120mm | ◎ Best season |
| November | 27℃ | 18℃ | 30mm | 〇 |
| December | 22℃ | 15℃ | 20mm | x Cold, air pollution |
Source: Hanoi climate, time difference, immigration, prohibited items, etc. (ANA)
*Temperatures and rainfall are guidelines for normal values. They vary by year.
Hanoi has loose four seasons
Hanoi is said to have four seasons, but summer and winter are long, while autumn and spring are short, about a month each. It varies by year, but the guideline is as follows.
- Mid-March to early May: spring
- Mid-May to September: summer
- October to November: autumn
- December to mid-March: winter
Winter turns cold, and summer stays above 38 degrees
Some may imagine that, hearing "Southeast Asian winter," the climate is one you can spend in a thin long-sleeved shirt.
But Hanoi's winter has days that stay below 10 degrees.If you carelessly sightsee in a thin jacket, you might catch a cold.
One or two days a year, there are days when a thick down jacket is needed.
Conversely, summer, May to July, is a harsh season with days above 35 degrees continuing.
Air pollution worsens in the city of Hanoi in winter
ハノイでは大気汚染が健康上の注意点になりますが、「市全体の平均AQIが200」「世界で最も汚い」と固定するのは不正確です。AQIは測定地点、時間、提供機関の尺度で変わるため、滞在日の公的観測と健康助言を確認してください。
Also, in winter the daylight hours are short and cloudy days are common.
For anyone who wants to sightsee on a clear day, or who has health concerns, avoiding this period is recommended.
The Best Seasons for Sightseeing in Hanoi Are March–April and September–November
3〜4月、9〜11月は比較的歩きやすい候補ですが、暑さ・雨・台風・大気質には年ごとの差があります。
The climate features of March to April
- Average high: 24 to 26°C
- Average low: 17 to 21°C
- Sunny rate: on the higher side, many days with continuing blue skies
The climate features of September to November
- Average high: 27 to 32°C
- Average low: 18 to 24°C
- Sunny rate: on the higher side, many days with continuing blue skies
10〜11月も日中の暑さ、降雨、湿度は変動します。「必ず乾燥して最適」と考えず、直前予報で服装を調整してください。
Watch out for typhoons
September to November has more days with good climate, butit overlaps with the typhoon season from mid-August into September.
There are days with very strong wind and rain, so caution is needed.
過去の台風被害は参考になりますが、旧稿の体験談として裏付けられないため、特定年の市内全域の状況とは断定しません。大雨時は冠水情報と交通機関の運行を確認してください。
Depending on the typhoon situation, ride-hailing apps like Grab can become unusable too. Check the weather forecast in advance and, on days with strong wind and rain, avoid forcing yourself to go out.
Times better avoided: June to August
From June to August, scorching heat above 35 degrees continues. It's also not unusual for humidity to exceed 90%.
For those who "can only go during this period," we recommend building a route centered on museums and indoor cafes.
When doing outdoor sightseeing, we recommend the early-morning hours. Evening sightseeing is recommended too, but some ruins and museums close early, so check the hours in advance.
In Vietnam, compared with Japan, you need to be careful with untreated water, raw vegetables, ice, undercooked dishes, and poorly stored food.
On hot days especially the risk of food poisoning rises, so take ample care.
Clothing and what to bring by season
Best season (September to November, March to April)
| Item | Necessity | Note |
|---|---|---|
| Thin jacket or cardigan | Essential | For the morning and evening chill |
| Short-sleeved T-shirt | Essential | It's warm during the day |
| Sneakers | Recommended | Essential for walking the Old Quarter |
| All-weather umbrella | Recommended | For sun and squalls |
| Sunscreen | Essential | UV is strong all year |
Rainy season (May to August)
| Item | Necessity | Note |
|---|---|---|
| Short-sleeved T-shirt | Essential | Quick-drying material recommended ◎ |
| Thin jacket or cardigan | Recommended | For the cold inside hotels and restaurants |
| All-weather umbrella | Recommended | For sun and squalls |
| Hydration gear | Essential | High risk of heatstroke |
| Hat and sunglasses | Recommended | UV protection |
Winter (December to February)
| Item | Necessity | Note |
|---|---|---|
| Jacket or sweater | Essential | It can drop below 10°C |
| Long-sleeved shirt | Essential | Layering is basic |
| Thick socks | Handy to have | For the chilly nights |
The best season for sights around Hanoi
The best season for sightseeing in the city of Hanoi
For those who want to enjoy walking the town, March to May and October to November are recommended.
Summer has high humidity and isn't suited to walking around town. And winter has low temperatures, but air pollution worsens.
The best season for Ha Long Bay sightseeing
March to May and October to November are recommended.
The winter of December to February is cold, and in the September typhoon season, cruise boats touring Ha Long Bay may be canceled.
The best season for Ninh Binh and Trang An
Trang An, called "the Ha Long Bay on land," and Ninh Binh, home to the old capital "Hoa Lu," are sightseeing spots you can reach within 2 hours by car from Hanoi.
Trang An is famous for tours you take by boat, butMarch to May and October to November are recommended.
出発7日前から確認する情報
- 平年値ではなく、時間帯別の気温・降水・雷・風予報
- 台風や熱帯低気圧の進路と航空会社の運航案内
- ハロン湾クルーズ、ボート、ロープウェイの運休情報
- 大気質指数と、持病・年齢に応じた健康助言
- 屋外施設の最終入場と雨天時の代替施設
- 冠水時に通らない道路とホテルまでの帰路
月別表は服装や日程のたたき台にはなりますが、個別旅行日の天候を予測するものではありません。取消・変更可能な予約を選び、屋外日程と屋内日程を入れ替えられる形にしておくと安全です。
Frequently asked questions
When is Hanoi's rainy season?
May to October is the rainy season. Rainfall peaks especially from June to August. During this period it rarely rains all day, but keep an umbrella ready for sudden rain.
How is traveling during Tet (Lunar New Year)?
Tet is late January to early February, but it varies by year. Since many Vietnamese return to their hometowns, the city of Hanoi goes quiet.
Many shops aren't open, but tourist spots are relatively empty, which you could call a hidden opportunity.
How does the climate differ between Hanoi and Ho Chi Minh City?
Hanoi has four seasons, and winter (January to February) cools to the low teens Celsius. Ho Chi Minh City has a tropical climate of 25 to 35°C year-round.
Choosing which one to go to based on your travel timing is one approach.
Is there a typhoon worry for a Hanoi trip?
熱帯低気圧や台風の影響時期は年により前後します。月だけで安全を判断せず、旅行前から毎日、公式気象情報、航空便、クルーズや観光施設の運行を確認してください。
Is Hanoi's winter really cold? Totally different from the Southeast Asia image?
In January, lows can drop below 10°C. Don't assume "it's Southeast Asia so summer clothes are enough." Be sure to bring warm clothing, even if thin.
