Nestled between sea and mountains, shaped by monsoon winds and stretching over 1,600 km of coastline from north to south, Vietnam experiences a tropical climate with many faces. Depending on the region and season, scorching heat, constant humidity, intense rainfall, typhoons and mosquitoes become part of daily life for residents… and travellers. To make the most of your stay in this fascinating country, it's essential to understand these climatic realities and adopt a few practical reflexes.

Tropical Heat in Vietnam

Vietnam experiences constant heat, particularly in the South where temperatures range between 30 and 35 °C year-round. In the North, summers are hot and humid, while winters are cooler, especially at altitude. The Central region experiences hot winds from Laos, intensifying the heat. During summer, the country averages 200 hours of sunshine per month, compared to 130 in winter.

Vietnamese people describe this heat through vivid expressions: "sun scorching the skin", "roasting heat", or "heat that makes the sky burst". These high temperatures, amplified by climate change, promote dehydration, heat stroke and can worsen certain illnesses.

To adapt:

• Wear lightweight, breathable clothing that provides coverage.
• Stay hydrated regularly, even if you don't feel thirsty.
• Avoid strenuous physical activity between 11am and 3pm.
• Protect yourself with a hat, sunglasses and sunscreen.

These simple steps will help you enjoy your stay while safeguarding your health.

Constant Humidity in Vietnam

One of the most striking aspects of Vietnam's climate is its constant humidity, particularly during the rainy season. In some regions, humidity levels can reach 90%, causing a persistent dampness: wet clothing, sweating without effort and difficulty keeping accommodation dry.

This atmosphere also encourages the growth of mould and the proliferation of mosquitoes. It increases health risks such as infections or diseases transmitted by water and insects, including dengue and malaria.

To better cope with this humidity, it's advisable to opt for quick-drying clothing and to regularly ventilate your accommodation to prevent mould. Use waterproof bags to protect your documents and electronic devices.

Tropical Rainfall in Vietnam

Vietnam is subject to a monsoon system that brings intense and sometimes violent rainfall, with distribution varying by region:

• In the North, the rainy season extends from April to September, peaking between July and October, a period when landslides, mudslides and impassable roads are frequent.
• The Central region experiences its heaviest rainfall from October to December, often accompanied by typhoons.
• In the South, precipitation occurs from May to October, generally in the form of sudden thunderstorms.

These episodes of heavy rainfall can cause flooding, major inundations, material damage, transport disruptions and communication outages, particularly in coastal provinces and the Mekong Delta. Climate change intensifies these phenomena further, making weather forecast monitoring essential.

To face these tropical rains, it's recommended to:

• Keep a sturdy poncho or umbrella with you
• Wear water-resistant shoes
• Check road conditions before any journey
• Follow local media updates carefully.

It's also important never to shelter under a tree during a storm and to follow local authorities' instructions when storms or typhoons threaten.

Typhoons in Vietnam

Vietnam is highly exposed to typhoons and tropical storms, especially in the Central and Northern regions, between July and November. These phenomena bring winds reaching up to 200 km/h, torrential rainfall sometimes exceeding 1.7 metres in 24 hours, and cause flooding, landslides, flash floods and power outages.

This vulnerability is explained by the East Sea, the formation of storms over warm waters exceeding 26 °C and the role of the Pacific subtropical anticyclone. The latter directs systems northward at the beginning of the season, then towards the Centre from September onwards.

To protect yourself, it's essential to monitor weather forecasts, avoid at-risk areas and plan a flexible itinerary. At home, you can limit damage by:

• Reinforcing doors, windows and roofing
• Using water-resistant materials
• Elevating electrical equipment
• Protecting openings
• Maintaining proper drainage.

When travelling, it's advisable to monitor official alerts, carry an emergency kit (torch, external battery, water, medicines) and strictly follow local authorities' instructions.

Mosquitoes in Vietnam

Vietnam's tropical and subtropical climate favours mosquito proliferation, particularly during warm and humid periods:

• In the North, such as in Hanoi and Sapa, mosquitoes are abundant between June and August, during the rainy season.
• In the Central region, notably in Hue and Hoi An, the most critical period is between October and November, when typhoons cause intense precipitation.
• In the South, such as in Ho Chi Minh City or the Mekong Delta, mosquito density peaks between May and October.

Certain mosquito species can transmit diseases, including dengue (very prevalent in urban areas), malaria (limited to rural border zones), as well as Zika and chikungunya (rarer but worth monitoring).

To protect yourself, it's recommended to wear long, light-coloured clothing, use appropriate repellents, sleep under a mosquito net, and avoid areas of stagnant water. Vietnamese people also use natural solutions such as citronella oil or neem leaves.

In case of mosquito bite, clean the area, soothe the inflammation and monitor for any symptoms. If fever, extreme fatigue or pain appears, it's imperative to consult a doctor quickly.