Quick Summary: Hanoi weather has four clear seasons, and the best time to visit is October to November, with 22.1–24.8°C and 9–13 rain days a month. Summer (May to September) is hot and wet at 27.4–29.6°C, while winter is cool and grey at 17.3–18.3°C.
Hanoi sits on the flat Red River Delta, so cool winter air and hot, wet summer air both roll in with little to stop them. That is why the same city can feel like a damp, cool autumn in January and a steam bath in July.
Hanoi Weather at a Glance
- Best months: October and November (22.1–24.8°C, 9–13 rain days a month).
- Average temperature: from 17.3°C in January to 29.6°C in June.
- Wet season: May to September, with 18–24 rain days a month. August is the wettest month (24 rain days).
- Cool season: December to February, 17.3–18.3°C, with grey skies and light drizzle.
Best Time to Visit Hanoi
October and November are the sweet spot for Hanoi weather. Temperatures are 22.1–24.8°C, rain days fall to 9–13 a month, and the air feels less sticky. In these months the milk flower trees (hoa sữa) also scent the streets around the Old Quarter.
December is a good backup. It is the driest month of the year with only 7 rain days, but it is cool at 17.9°C on average. March and April are pleasant (21.7–24.8°C), though you should expect 12 rain days a month and light drizzle. Avoid July to September if you dislike heat and heavy rain: August alone has 24 rain days.
Hanoi Weather by Season
- Winter (December–February): 17.3–18.3°C, 7–10 rain days a month. Cool, damp and often overcast.
- Spring (March–April): 21.7–24.8°C, 12 rain days a month. Warmer days with light drizzle.
- Summer (May–September): 27.4–29.6°C, 18–24 rain days a month. Hot, humid, with heavy afternoon showers.
- Autumn (October–November): 22.1–24.8°C, 9–13 rain days a month. The most comfortable season, with clearer skies.
For long-term charts and hot and cool season dates, see the WeatherSpark climate data for Hanoi.
Daily Weather & Humidity Insights
- Humidity: it stays high all year, often around 80% in winter, so summer heat feels even stronger than the number on the thermometer.
- Day and night gap: in January, days are around 20°C and nights near 14°C. In June, highs reach about 33°C and nights stay near 26°C.
- Winter feel: the cold is damp rather than freezing, and some older buildings have no heating, so a 14°C night can feel colder indoors.
- Summer storms: short, heavy showers can flood low streets for an hour or two.
What to Wear and Pack
- December to February: a light jacket, a scarf and layers you can add or remove.
- May to September: breathable cotton or linen, a sun hat, sunscreen and a compact umbrella.
- October–November and March–April: light layers and one thin jacket for the evenings.
- Shoes: comfortable walking shoes with grip, because wet pavements get slippery.
Essential Local Tips
- Beat the heat and the crowds: walk the Old Quarter and Hoan Kiem Lake between 6 and 8 am. In summer, plan museums and cafés for 12 to 3 pm.
- Watch for typhoons and floods: the risk is highest from July to October. Heavy rain can flood streets and delay day trips to Ha Long Bay or Ninh Binh, so keep a flexible plan.
- Chase the seasons: October and November bring the scent of milk flowers and soft light on West Lake, which makes them great for slow walks and photos.
Ready to plan the rest of your trip? See more things to do in our full Hanoi travel guide.
