Living · Environment
Climate and pollution by city
The four climate zones (rough)
- Northern (Beijing, Tianjin, Xi'an, Harbin) — humid continental. Hot humid summers, dry cold winters. Spring dust storms.
- Central (Wuhan, Nanjing, Shanghai, Chongqing) — humid subtropical. Hot humid summers, cool damp winters. Long rainy season in early summer.
- Southern (Guangzhou, Shenzhen, Xiamen) — humid subtropical to tropical. Long hot summers, mild winters, typhoon season July–September.
- Western (Kunming, Lhasa, Urumqi) — varied. Kunming is plateau-temperate (year-round mild). Lhasa is high-altitude alpine. Urumqi is continental dry.
Air quality summary by city
| City | Annual mean PM2.5 (μg/m³, 2024) | Trajectory | ||
|---|---|---|---|---|
| Beijing | ~30 | Improved 50%+ since 2013 | ||
| Shanghai | ~28 | Steady improvement | ||
| Guangzhou | ~26 | Among cleaner megacities | ||
| Shenzhen | ~22 | Cleanest tier-1 | ||
| Chengdu | ~38 | Stable; basin geography pins haze | ||
| Wuhan | ~36 | Slowly improving | ||
| Xi'an | ~45 | Among most polluted tier-1; winter spikes | ||
| Harbin | ~38 | Coal-heating winter spikes | ||
| Kunming | ~22 | Among cleaner | ||
| Lhasa | ~12 | Among cleanest | ||
| Urumqi | ~50 | Industrial + topography | ||
| Hong Kong | ~18 | Cleaner than mainland tier-1 |
WHO guideline: 5 μg/m³ annual mean. Most Chinese cities exceed this; the trend is broadly improving.
Worst seasons
- Winter (Nov–Feb) in northern cities — coal heating + temperature inversion + low wind = winter haze. Beijing's worst days run AQI 200+.
- Spring (Mar–Apr) in northern cities — dust storms from the Gobi.
- Late summer (Aug–Sep) in central / southern cities — ozone (different pollutant; bothers some people more than PM2.5).
- Year-round in the Sichuan basin and the Lanzhou/Xining corridor — persistent low-grade haze due to topography.
The cleaner seasons
- Late September to early November in north and central — clearest of the year.
- Spring (Apr–May) in south — clear before summer typhoons.
- December–February in southern cities — dry, mild, clean.
What helps long-term
- Air purifier at home and ideally office (¥800–¥3,000 for a domestic unit; HEPA-rated).
- AQI app habit — check before exercising outdoors.
- N95 / KN95 masks on AQI 150+ days.
- Sealed windows in older Beijing apartments.
Recent policy shifts
- Coal-to-gas conversion in residential heating (driver of Beijing's improvement).
- Heavy-industry relocation away from major cities (steel mills, cement plants moved out of Beijing-Tianjin-Hebei).
- EV adoption in tier-1 cities reducing road-vehicle emissions.
- Emissions trading scheme covering thermal power generation.
The trajectory continues to improve, more slowly than the 2013–2017 step change.
Climate change
Warmer winters in the north (less reliable heating-bills planning), more extreme summer heat events nationally, longer monsoon seasons in the south, more frequent typhoons reaching further north (Hong Kong, Shanghai, Tianjin).
Verified May 2026