The weather in Hanoi features a warm humid subtropical climate (Köppen Cwa) with plentiful precipitation.
The weather has a clear difference between hot and cold seasons and can be divided into 4 seasons: spring, summer, autumn and winter. The hot season starts from mid-April to mid-September, with high temperature, humid and heavy rain. October often is dry and cool. From mid-November until the ends of March is cold season. Weather is cold, dry and rarely rain from the end of November until January. It is also cold during February and March but humid with drizzle can lasted for weeks. September and November is autumn, due weak Northeast wind from Siberia, Russia. However, due to the strong influence of the monsoon, the start and the end of each season are unevenly distributed between the years, so the division of months is only relative.
(Read More: Get Around in Hanoi)
– Average temperature in Winter: 16,5 °C (61,7 oF) (Record low: 2,7 °C (36,9 oF))
– Average temperature in Summer: 29,5 °C (85,1 oF) (Record high 43,7 °C (110,6 oF))
– The average annual temperature is 23.6 °C (74 °F)
– Hanoi averages 1,680 millimeters (66.1 in) of rainfall per year
Winter in Vietnam in fact just is cool and pleasant for visitors from Europe or North America, countries which is much lower temperature than Vietnam. The best time to visit Hanoi is from October to early January next year, the temperature below 18 oC and the dryness is suitable for outdoor activities. However, the difference in temperature between day and night in winter is quite large, so visitors should bring a coat if you intend to return to the hotel late.
The first 3 months are called spring although the weather is still quite cold. Though long drizzles are not a major impediment to tourist, preparing a waterproof jacket is a good idea to keep your body from getting wet or cold if you want to visit outside for long periods of time.
Summer is not a tourist season in Vietnam due to hot weather with unannounced showers. Many services for tourists are much cheaper than normal to attract tourists during low season, Therefore, going to Hanoi for summer is a good idea if you want to save your budget. Just don’t forget to drink enough water and always carry sunscreen, hat, sunglasses when being outside.