Air Quality
Pollution level of the air you breathe
What is it?
The Air Quality Index condenses concentrations of key pollutants — fine particles (PM2.5, PM10), ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide — into one number describing how clean or polluted the air is.
How we measure it
US AQI from the Open-Meteo air-quality feed (CAMS model), where higher numbers mean more polluted air.
US EPA AQI categories
- 0–50GoodAir poses little or no risk
- 51–100ModerateAcceptable; unusually sensitive people take care
- 101–150Unhealthy for sensitive groupsChildren, elderly, heart/lung conditions affected
- 151–200UnhealthyEveryone may begin to feel effects
- 201–300Very unhealthyHealth alert — serious effects for all
- 301+HazardousEmergency conditions
Within safe range
Below 50, outdoor activity is safe for everyone, including long or intense exercise.
Beyond the range
Above 100, fine particles penetrate deep into lungs and the bloodstream — aggravating asthma, raising heart-attack and stroke risk, and reducing lung function. Effects compound with exposure time and exercise intensity, since you inhale far more air when active.
Precautions
- At 100+: sensitive groups move long or intense activity indoors.
- At 150+: everyone shortens outdoor exertion; prefer mornings when ozone is lower.
- Close windows during pollution episodes; use HEPA filtration if available.
- A well-fitted N95/FFP2 mask filters most fine particles outdoors.
- Don't add to indoor pollution — avoid burning candles/incense on bad-air days.