If you plan to visit the entire country, the best months are October-December, when temperatures are relatively mild and nights are cool (highs around 88 F/31 C, lows around 71 F/22 C). Temperatures are lower in the northern part of the country, so take along a sweater and a wind- and rain-protective jacket. January-March is foggy and drizzly in the north, but sunny and pleasant in the south. The mountains can be quite cold in winter, with occasional snowfall at higher elevations. May-September is the hot, humid monsoon season in the south, when temperatures reach 92 F/33 C and fall to only about 76 F/24 C. Be warned that monsoons can turn roads to mud, and keep your travel plans flexible if visiting at that time of year.
What to Wear
Pack lightly when preparing for your trip to Vietnam. Clothes are inexpensive to purchase as needed, depending on where and when you choose to travel. Here are a few items you won't find available, though:
Sweaters and hoodies—you'll want these for evenings in the Central Highlands at most times of the year, and in the north during the winter months.
Comfortable shoes—both sandals for warm weather and sneakers or trekking shoes for cooler climes and rougher terrain.
Cosmetics—most face creams for women in Vietnam have names such as "white beauty" or "pale as moonlight," which indicates that it contains a white pigment. A streaky white complexion is probably not the look you're aiming for.
If you're traveling for business, prepare to dress sharply in well-tailored business suits (for both men and women). It may be easier (and more fun) to have a couple of suits custom-made for you by the expert tailors in Hanoi, Ho Chi Minh City or Hoi An. The price for a bespoke suit in Vietnam is a fraction of what you'd pay for off-the-rack ones in the U.S. Silk ties are a bargain, too, and are sold in most hotel boutiques. Do remember to take business shoes. The only conservative office shoes available in Vietnam are second-hand from Europe and North America. Women's shoes are considerably easier to find, though larger sizes are not.
Most all Vietnamese dress conservatively in clean, pressed clothes with short- or long-sleeved shirts (not sleeveless or halter-top) and full- or capri-length pants. Tight or revealing clothing is not acceptable, even in the major cities.
