Vietnam’s weather is rather a complicated story with distinct weather patterns in the north, centre and the south. The north of the country has a winter lasting from November through to April with temperatures ranging from 12-18 Celsius. During this time it is generally dry though grey skies and drizzle are common in February and March. Summers last from May to October and are very hot and humid with frequent heavy rain and temperatures averaging 30 Celsius.
Meanwhile in the centre of the country it is usually dry and hot from February to August with temperatures reaching the mid 30s Celsius. Most the rain in the central regions falls from September to January.
In the south the rainy season lasts from May to November with the rain usually coming in short, heavy bursts in the afternoon. The dry season runs from December through to the end of April with the temperatures increasing in March and April before the rains arrive. The average annual temperature in the south is 28 Celsius and it rarely falls below 20 Celsius.
For visiting birders wanting to cover the north and the south the best time to aim for is from the start of December through to the end of April. Over-wintering birds should be around for most of this period and forest birding is generally more comfortable in the drier conditions with birds being more vocal in the early months of the year and easier to locate.