Hanoi's climate

Hanoi is located in northern region of Vietnam, situated in the Vietnam’s Red River delta, nearly 90 km (56 mi) away from the coastal area and Vietnam is on the eastern Indochina Peninsula between the
latitudes 8° and 24°N, and the longitudes 102° and 110°E. Vietnam's land is mostly hilly and densely forested, with level land covering no more than 20%. Mountains account for 40% of the country's land area, and tropical forests cover around 42%. 

This location has certain impacts on the climate of Hanoi. Hanoi features a warm humid subtropical climate with plentiful precipitation. The city experiences the typical climate of northern Vietnam, where summers are hot and humid, and winters are, by national standards, relatively cold and dry. Hanoi averages 1,680 millimetres (66.1 in) of rainfall per year, the majority falling from May to September. The city is usually cloudy and foggy in winter, averaging only 1.5 hours of sunshine per day in February. Extreme temperatures have ranged from 2.7 °C (36.9 °F) to 40.4 °C (105 °F).

Because of the subtropical climate, the amount of visitors to Hanoi is huge in autumn. Some people from European countries even said that  they will be roasted chicken if they come to Vietnam in summer. However, each season has its own beauty so you should consider carefully before traveling.