How we know: Sources are listed at the end. Climate facts come from the cited encyclopaedia pages, visa rules and regional seasons from Wikivoyage, on-the-ground prices from Numbeo's crowd-sourced data. Fares are not quoted; the route pages show today's price.
Vietnam is 1,000 miles long and has three climates, so there is no single best month. There is a best month for each region, and a couple of weeks (Tet, the lunar new year) when the whole country is expensive and half-closed. Plan by region, avoid Tet unless you want it, and the rest falls into place.
Three regions, three calendars
North (Hanoi, Ha Long Bay, Sapa). A monsoon-influenced subtropical climate with real seasons: a cool, dry winter from December to February (January averages about 16°C / 61°F), a drizzly spring in March–April, a hot, wet summer from May to September (July averages about 29°C / 85°F), and a warm, mild autumn in October–November; most of the roughly 1,600 mm of annual rain falls May to October (Hanoi). Wikivoyage calls spring (March–April) and autumn (October–December) the pleasant seasons (Wikivoyage: Vietnam). Best: October–November and March–April. Sapa's mountains can be genuinely cold in winter.
Central coast (Hue, Da Nang, Hoi An). The odd one out. The northeast monsoon brings strong winds, big swells and rain from September to February, which Wikivoyage describes as "a miserable and difficult time to travel through Central Vietnam"; summers are hot and dry (Wikivoyage: Vietnam). Best: February to August, with March–May the most comfortable.
South (Ho Chi Minh City, the Mekong Delta, Phu Quoc). Tropical, about 28°C / 82°F year-round, with a dry season from December to April and a rainy season from May to November that brings roughly 1,800 mm of rain over about 150 rainy days (Ho Chi Minh City). Wikivoyage rates December–February the most pleasant, with March–April hot and dry (Wikivoyage: Vietnam). Rainy-season showers are usually short afternoon bursts rather than all-day rain.
Putting the regions together
- Whole-country trip, best overall weather: February to April. The north is mild, the centre is dry, the south is at the end of its dry season.
- North and centre only: October–November or March–April.
- South and beaches only: December to March.
- Summer travel (June–August): the central coast is at its best; the north and south are hot and wet but perfectly workable, and prices are lower.
Tet: the week to plan around
Tet, the lunar new year, falls in late January or February and is the biggest holiday of the year. Domestic flights, trains and hotels fill with returning Vietnamese, many restaurants and shops close for several days, and prices rise across the board. Either arrive for the celebrations knowing that, or avoid the week either side.
Getting there from the US
Vietnam Airlines flies nonstop between Ho Chi Minh City and San Francisco; everything else connects, most commonly through Tokyo, Seoul, Taipei, Hong Kong or Singapore, all of which have frequent service to Ho Chi Minh City and Hanoi (Tan Son Nhat International Airport). From the West Coast expect 16–20 hours door to door with one connection; from the East Coast, 20–24. Flying into one end of the country and out of the other (open-jaw) saves a day of backtracking. Check current fares on LAX to Ho Chi Minh City, SFO to Ho Chi Minh City, SFO to Hanoi and JFK to Ho Chi Minh City.
When fares tend to be lowest
US demand for Vietnam peaks over Christmas and New Year, at Tet (driven by the Vietnamese-American community), and in the northern summer. The quieter periods are September–November and late April to early June, which also happen to be good weather windows for the north and the centre respectively. Long-haul Asia fares reward early booking; watch from five or six months out and set a price alert at a target below today's fare with flexible dates on.
Entry requirements for US citizens
US citizens need a visa. The practical route is the e-visa from the official portal (evisa.gov.vn), which Wikivoyage lists at $25 single-entry or $50 multiple-entry, valid for up to 90 days, with processing typically around three working days; print copies for entry and exit (Wikivoyage: Vietnam). Apply on the government site only; third-party sites charge more for the same form. Rules change, so confirm before you book.
What it costs on the ground
Vietnam is one of the cheapest countries in the world for travellers. Numbeo's crowd-sourced figures for Hanoi put a meal at an inexpensive restaurant at about ₫52,500, a three-course mid-range dinner for two at ₫550,000, a cappuccino at roughly ₫48,800 and a single local transport ticket at ₫10,000 (Numbeo Hanoi). Convert at today's rate and a day of eating well costs less than a single meal in a Western capital.
FAQ
What is the best month to visit Vietnam? For the whole country, February to April. For the north alone, October–November; for the central coast, March–May; for the south, December to February.
When is the rainy season in Vietnam? May to November in the south, May to September in the north, and September to February on the central coast.
Do US citizens need a visa for Vietnam? Yes. The e-visa from the official government portal is valid for up to 90 days.