The period between October and April is generally considered the best time to visit Hanoi, this being the capital of the country of Vietnam. Compared to the hot and humid summer months of May to September, during which temperatures reach uncomfortable highs, temperatures range generally between 18°C and 25°C, in the range of 64°F to 77°F, from dry December through to February, making it ideal for all activities involving excursions or outdoor activities. Also, you should be warned that December and January are quite cold and sometimes raining, but February begins warming up. Customize your tour according to your preferences, for Hanoi has a distinct charm in every season.
It generally depends on personal weather preference and crowd size: best time to visit Hanoi is the spring months, that is, March-April, and fall months, meaning October-November. These are the times for pleasant weather, with moderate temperatures and low humidity, making it very convenient to sightsee and engage in outdoor activities.
Spring (March-April): Chennai, a little warmer than most other months, is engulfed in celebration in Hanoi, as the Lunar New Year (Tet) will occur in late January or early February.
Autumn (October-November): The prime months for travel, wherein the weather is comfortable with fair skies making swingin around the city and the countryside very pleasant.
Hanoi can get pretty hot and steamy during the height of May-September but it can swing from somewhat chilly and foggy in the winter months from December through February-the window of best visit being around October-November, before the rest of the hordes arrive.
Time is not the only factor that would influence one when to visit Hanoi; the season, personal preferences, and particular planned activities on a trip should also be taken into consideration.
1) Winter (December-February): It is milder and agreeable in this period in Hanoi, where temperatures range between 20°C and 25°C (68°F and 77°F). It is really a wonderful time to explore the historical places in the city and indulge in outdoor activities such as hiking, biking, and visiting such well-known places as Ho Chi Minh Mausoleum and War Remnants Museum. Some attractions may operate at limited hours due to winter storms or special events.
2) Spring (March-May): March through May generally sees the temperature rising, with highs averaging around 29°C to 34°C during yet another beautiful time to visit, with the city in this time of the year turning into a vibrant, green-colorful spectacle. While now can follow cherry blossoms blooming through the city, you might enjoy various outdoor festivals, plus local central markets such as Hoa Loa, where fresh fruit and some handicrafts can be bought.
3) Summer time (June-August): Sayah Hanoi sees the hottest months from June to August-it could invariably get unbearable and hot; most of the time, the temperatures actually rise to up over 30°C (86°F) in peak summer. This is the time for swimming and surfing and climbing to do outdoors, with many of the attractions here also having discounts for tourists during this time. Just bring in liters of water and wear light stuff, or you might end up dead at the wrong time!
4) Autumn (September-November): Temperatures cool sometime during September to November, making Hanoi great for the tranquility seekers and a good time for this season. During that time, it is quite comforting at 23°C to 27°C (73°F to 81°F)-just perfect for stalking the city's avowed autumn colors, strolling past quiet lanes, and sampling some local cuisine from street vendors.