Like its neighbouring countries it does in fact have three fairly distinct seasons and the season that falls between winter and summer is generally classed as the rainy season seeing significant levels of precipitation as well as high temperatures and humidity. However, being located near the South China sea, Hanoi experience miserably cold and wet winters and the countryside can often look bleak covered in mist until April.
From a visitor perspective, any time is okay to take a holiday in Hanoi but it very much depends on your own tolerance of heat or rain and humidity as to when you decide to go. The early months of the year see the temperatures picking up and rainfall as its lowest so may choose to take their holiday at this time.
