As a long narrow country, Vietnam’s climate varies depending on if you are in the north, central areas, or south, which is great for travelers as the weather is always perfect somewhere.
In the north, May to October is hot, humid and wet with temperatures invariably between 25 and 32 °C (77-90°F). Rainfall is usually over 150 mm per month in Hanoi, the nation’s cultural capital, though it peaks in July at almost 250 mm per month. The heat of the north, particularly inland, gets too hot for some and many people chose this time to head for the cooler areas such as the beautiful Halong Bay, a coastal area set among towering limestone cliffs, and also a Unesco world heritage site, which receives an almost constant sea breeze.
The central region of Vietnam experiences a hot and dry ‘winter’ from mid-January to mid-August, with March, April, and May the best times to visit as the central highlands are a lot milder than the much more stifling heat suffered in the south, where it can reach 40°C (104°F). Temperatures in central areas are between 20 and 25 °C (68- 77°F) in January, steadily rising to a peak of around 25 to 35 °C (77-95°F) in June. Unlike the north and south, central areas receive almost no rainfall at this time. It is a fine time to visit ancient capital of Hue, the charming Unesco world heritage site of Hoi An, or the beautiful white sands of Lang Co replete with shady palm trees.
In the south, May to October is monsoon season, and it can be quite humid in the ‘Rice Bowl’ of Vietnam. Temperatures are usually between 24 and 33 °C (75-91°F) , with rainfall of around 100 mm per month, the brief heavy showers rarely disrupting travel – but regions around the Mekong may occasionally flood. September or early October sees Mid-Autumn Festival (full moon between September and October): a harvest festival celebrating that sees dragon and lion dances performed across the country with many wish lanterns being hung and lit.