Heat waves are more than discomfort — they change the chemistry and physics of the air. Stagnant high pressure reduces wind that would disperse pollution. Strong sun drives ozone formation. Dry heat lifts dust; humid heat can trap particles under haze. Heat wave air quality routinely makes headlines from Phoenix to Athens to Delhi.
Ozone and stagnation
On cloudless hot days, afternoon ozone often peaks even when morning PM2.5 looked fine. Weak overnight mixing lets particles linger into the next morning. Urban heat islands keep nights warm, slowing recovery.
Protecting yourself
- Check AQI and heat index together — exertion in orange air plus 35°C is high risk.
- Exercise before 9 a.m. when both temperature and ozone are lower.
- Stay hydrated; pollution and heat both stress the cardiovascular system.
- Use AC or fans indoors with windows closed when outdoor AQI is poor.
- Follow official heat and air quality alerts — doubly important for elderly and chronically ill.
Track hourly AQI during heat waves on Aether — afternoon readings often differ sharply from dawn.
Check live air quality on Aether