China Air Quality: What Travellers Should Know (and When a Mask Helps)

Where to check live air quality in China and Asia

The Air Quality Index (AQI) changes hour by hour, so use a live source rather than an annual average:

• aqicn.org — the World Air Quality Index project, with a real-time map covering thousands of monitoring stations across China and Asia.
• IQAir — live city rankings and 7-day forecasts, useful for planning outdoor days on a trip.
• The US Embassy and Consulate monitors in Beijing, Shanghai, Guangzhou, Chengdu and Shenyang publish independent hourly PM2.5 readings, available through both sites above.

Check the forecast for your actual destination and travel dates. Air quality varies enormously between cities and between seasons — a national average tells you very little.

How to read the AQI numbers

The AQI runs from 0 to 500. Here is the standard US EPA scale most international sites use, and what each band means in practice for a visitor:

AQI	Category	What it means for you
0–50	Good	No restrictions. Enjoy being outdoors.
51–100	Moderate	Fine for most people; unusually sensitive individuals may notice effects during heavy exertion.
101–150	Unhealthy for sensitive groups	Children, older adults, and anyone with asthma or heart/lung conditions should limit prolonged outdoor exertion. A well-fitted mask helps this group.
151–200	Unhealthy	Everyone may begin to feel effects. Reduce prolonged outdoor exertion; this is the level where wearing a particulate mask outdoors becomes a sensible default for anyone.
201–300	Very unhealthy	Avoid outdoor exertion. Wear a well-sealed mask for any time spent outside.
301+	Hazardous	Stay indoors with filtration where possible. Mask up for any unavoidable outdoor exposure.

Note: China’s official domestic AQI uses slightly different breakpoints from the US EPA scale, so Chinese apps can report a lower number for the same air. The US Embassy readings and the sites above use the US scale.

How good is China’s air quality now?

Much better than its reputation — and still not good by international health standards. Both things are true. Since China declared its “war on pollution” in 2013–2014, average PM2.5 levels in major eastern cities have fallen substantially. Recent national averages put China in the “moderate” AQI band on a typical day.

The catch: the WHO’s 2021 guideline for annual PM2.5 exposure is just 5 µg/m³, and China’s national average remains several times above that. “Moderate on average” also hides big swings — a clear week can be followed by an AQI-200 episode when weather traps pollution or dust arrives.

Is Beijing still smoggy?

Far less than it used to be. The “airpocalypse” episodes of 2013–2015 that made global headlines are rare now; Beijing’s annual PM2.5 has fallen by well over half since then. But smog hasn’t disappeared — it has become seasonal. Winter coal-heating months (roughly November–February) and spring dust storms still produce multi-day unhealthy stretches. If your trip falls outside those windows, the odds of consistently decent air are much better than a decade ago.

Which parts of China have the cleanest air?

Generally the south and the coast. Cities such as Haikou and Sanya on Hainan island, along with Kunming and Lijiang in Yunnan, regularly top China’s clean-air rankings. The North China Plain — including Beijing, Tianjin and Hebei province — and industrial corridors along the Yellow River tend to record the highest pollution, especially in winter and spring.

Dust-storm season: March to May

Each spring, winds carry dust from the Gobi Desert and Mongolia across northern China. April 2025 brought China’s worst dust and sand storm in a decade by intensity, duration and reach, according to the World Meteorological Organisation’s Airborne Dust Bulletin: hourly PM10 concentrations exceeded 1,000 µg/m³ across northern China, and reached 3,000–4,000 µg/m³ in some places. For scale, the WHO’s 24-hour guideline for PM10 is 45 µg/m³.

Two practical points for travellers:

• If you’re visiting Beijing, Xi’an or anywhere in the north between March and May, build flexibility into outdoor plans and check the AQI forecast daily.
• Dust storms are a coarse-plus-fine particle event. A loosely fitting mask does little; the seal against your face matters as much as the filter inside.

At what AQI should you wear a mask?

A reasonable rule of thumb, consistent with the EPA guidance in the table above:

• AQI 100+ — sensitive groups (children, older adults, asthma or heart/lung conditions) benefit from a well-fitted particulate mask outdoors.
• AQI 150+ — a mask outdoors becomes a sensible default for everyone, especially if you’ll be walking, cycling or exercising.
• AQI 200+ — limit time outside and wear a well-sealed mask when you can’t.

One caveat that matters more than the filter grade printed on the box: a mask only performs to its rating if it seals to your face. Gaps around the nose and cheeks let unfiltered air bypass the filter entirely.

Don’t forget the flight itself

The trip to China starts hours before you meet any smog. On a long-haul flight, a well-fitted mask earns its place three times over:

• Dry cabin air. Aircraft cabin humidity is far lower than most indoor environments. A mask retains some of the moisture from your own breath, so your nose and throat stay less parched over a 10–12 hour flight.
• Coughing neighbours. You can’t choose who sits beside you. A sealed mask reduces your exposure to airborne droplets from fellow passengers — the same principle behind the hospital studies of the Totobobo design.
• Ready on arrival. The same mask goes straight from the cabin into the arrivals hall and the taxi queue — no separate gear for the flight and the destination.

Live AQI data: aqicn.org and IQAir. Health bands: US EPA Air Quality Index. WHO air quality guidelines (2021): annual PM2.5 of 5 µg/m³; 24-hour PM10 of 45 µg/m³. Dust storm figures: WMO Airborne Dust Bulletin, 2026. Filtration figure: Nelson Labs particle filtration efficiency test at 0.1 micron.