Allentown Air Quality in 2025

In 2025, Allentown's air quality (Allentown-Bethlehem-Easton, PA-NJ area) had a median daily AQI of 42 (Good) across 365 monitored days. 3 days (0.8%) reached Unhealthy for Sensitive Groups or worse, 244 were Good, and the year's peak AQI was 122 (Unhealthy for Sensitive Groups). Ground-level ozone set the daily AQI on 227 of those days. The cleanest month of 2025 was October (median AQI 31, 0 days above 100) and the worst was June (median 52, 2 days above 100, peak 122).

42
Median AQI
Good
3
Days above AQI 100
0.8% of 365 days
67
90th percentile AQI
worst 1 day in 10
122
Peak AQI
Unhealthy for Sensitive Groups
O3
Main pollutant
227 of 365 days
244
Good days
66.8% of days
  • Good: 66.8%
  • Moderate: 32.3%
  • Unhealthy for Sensitive Groups: 0.8%
  • Unhealthy or worse: 0.0%

Reduce Indoor Ozone in Allentown

Today's main pollutant in Allentown is ground-level ozone (AQI 44). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.

Recommended: Levoit Core 300True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft

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QUICK ANSWER

How was Allentown's air quality in 2025?

Good on a typical day: median AQI 42, with 3 days above AQI 100 out of 365 monitored — the 3rd cleanest of 7 years on record for the area.

  • Peak AQI in 2025: 122 (Unhealthy for Sensitive Groups).
  • Ground-level ozone was the main pollutant on 227 days.
  • Cleanest month: October; worst: June.

Frequently asked questions

What was the average AQI in Allentown in 2025?

EPA's Air Quality System puts Allentown's (Allentown-Bethlehem-Easton, PA-NJ) median daily AQI for 2025 at 42, which is Good. 3 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 122.

Which month had the worst air quality in Allentown in 2025?

The cleanest month of 2025 was October (median AQI 31, 0 days above 100) and the worst was June (median 52, 2 days above 100, peak 122).

Was 2025 a good or bad year for Allentown's air?

Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 3rd cleanest by days above AQI 100. 2025's median of 42 is below the area's typical annual median of 46.

Allentown month by month in 2025

Allentown air quality month by month, 2025 (Allentown-Bethlehem-Easton, PA-NJ, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January3139087PM2.5
February2838075PM2.5
March3143065O3
April3044097O3
May31390100O3
Juneworst30522122O3
July3149088O3
August31431108O3
September3044058O3
Octobercleanest3131071O3
November3036089PM2.5
December3139089PM2.5

How 2025 compares

Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 3rd cleanest by days above AQI 100.

2025's median of 42 is below the area's typical annual median of 46.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Allentown

The latest EPA AirNow observation puts Allentown's AQI at 44 (O3). The figures above are multi-year annual statistics, not today's reading.

View current Allentown air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Allentown-Bethlehem-Easton, PA-NJ), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.