Vietnam Air Quality Index (AQI)
Vietnam is one of Southeast Asia's most rapidly industrializing economies — and its air quality reflects that. Hanoi is among Asia's most polluted capitals, driven by 75 million motorbikes nationwide, coal power at 46% of electricity, and transboundary pollution from China. The north bears the heaviest burden; the central coast enjoys relatively cleaner air.
Most Polluted Cities
- HanoiAQI 148
- Hai PhongAQI 128
- Ho Chi Minh CityAQI 115
Cleanest Cities
- Da NangAQI 68
- Can ThoAQI 98
- Ho Chi Minh CityAQI 115
Northern Vietnam
Hanoi
Hanoi · Pop. 8.2M
Hanoi is Vietnam's most polluted city and consistently among Southeast Asia's worst. Winter months (Oct–March) see PM2.5 regularly exceed 100 μg/m³ due to cold air masses from China bringing pollution south, combined with local emissions. Vietnam has 6.5 million motorbikes in Hanoi alone — a primary pollution source.
Hai Phong
Hai Phong · Pop. 2.2M
Vietnam's third-largest city and largest port. Industrial activity including steel, cement, and chemicals makes Hai Phong one of northern Vietnam's most polluted cities. The port handles over 100 million tonnes of cargo annually, contributing significantly to ship exhaust and dust emissions.
Central Vietnam
Da Nang
Da Nang · Pop. 1.2M
Vietnam's third-largest city and premier coastal resort. Da Nang's position on the South China Sea provides consistent wind clearing. The city has actively promoted clean energy and sustainable tourism. AQI remains moderate year-round — one of Vietnam's cleaner large cities.
Southern Vietnam
Ho Chi Minh City
Ho Chi Minh City · Pop. 9.3M
Vietnam's economic capital and largest city. HCMC's air quality is better than Hanoi due to its southerly position and tropical monsoon patterns. However, 9 million motorbikes make it one of Asia's most congested cities. The dry season (Dec–Apr) brings elevated AQI from Mekong Delta agricultural burning.
Can Tho
Can Tho · Pop. 1.3M
The Mekong Delta's largest city. Can Tho sits in the heart of Vietnam's rice bowl — the twice-yearly rice straw burning after harvest is a major pollution event. The Mekong River and delta canals provide some ventilation, but burning season in Nov–Dec and May–Jun regularly pushes AQI above 150.
Hanoi: The Motorbike and Coal Problem
Hanoi has 6.5 million registered motorbikes — nearly one per person. Millions more unregistered bikes and aging buses contribute to a massive vehicle emission load. But transport is only part of the story.
- Vietnam gets 46% of electricity from coal; major plants cluster in the Red River Delta near Hanoi
- Transboundary flow: northeast winter monsoon carries pollutants from China's industrial heartland southward
- Rice straw burning: 10 million tonnes of rice straw burned annually in northern Vietnam, much of it near urban areas
- 2023 data: Hanoi exceeded WHO 24-hr PM2.5 guideline on 220+ days
Vietnam's National Action Plan on Air Quality (2021–2025) targets replacing aging motorbikes and expanding emission standards, but enforcement remains weak in rural areas. Hanoi is piloting electric bus routes under a World Bank-supported program.
Vietnam Air Quality by Season
Cold northeast monsoon traps emissions. Hanoi and Hai Phong at their most polluted. Avoid prolonged outdoor exercise. PM2.5 can exceed 150 μg/m³.
Southwest monsoon brings cleaner maritime air. Hanoi improves significantly. Still above WHO guidelines but far better than winter.
HCMC sees elevated AQI from Mekong Delta burning and stagnant air. Still better than the north. Da Nang remains relatively clean.
Monsoon rains clear the air in HCMC and the Mekong Delta. Best time for outdoor activities in southern Vietnam.