Moderate Air Quality (AQI 51–100)

Air quality is acceptable, but some pollutants may concern unusually sensitive individuals.

0–50 51–100 101–150 151–200 201–300 301–500

What Does This Mean?

Most people will not experience health effects. PM2.5 is typically 12.1–35.4 µg/m³ — above the WHO annual guideline of 5 µg/m³ but within the EPA 24-hour standard of 35 µg/m³. This level is common in cities with moderate traffic.

Who Is Affected?

  • People with asthma or chronic respiratory conditions
  • People who are unusually sensitive to ozone
  • These individuals may experience mild symptoms during prolonged outdoor exertion

What Should You Do?

  • Most people: no precautions needed
  • Sensitive individuals: consider reducing prolonged outdoor exertion if experiencing symptoms
  • Running or cycling is generally fine for healthy adults
  • Air purifiers optional but beneficial if indoor PM2.5 is elevated

Key Pollutants at This Level

PM2.5 and ground-level ozone are the most common drivers of AQI 51–100. Ozone peaks in warm afternoons; PM2.5 peaks in morning and evening traffic.