Allentown Air Quality in 2020

In 2020, Allentown's air quality (Allentown-Bethlehem-Easton, PA-NJ area) had a median daily AQI of 44 (Good) across 366 monitored days. 1 day (0.3%) reached Unhealthy for Sensitive Groups or worse, 234 were Good, and the year's peak AQI was 117 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 236 of those days. The cleanest month of 2020 was September (median AQI 39, 0 days above 100) and the worst was December (median 53, 1 day above 100, peak 117).

44
Median AQI
Good
1
Days above AQI 100
0.3% of 366 days
61
90th percentile AQI
worst 1 day in 10
117
Peak AQI
Unhealthy for Sensitive Groups
PM2.5
Main pollutant
236 of 366 days
234
Good days
63.9% of days
  • Good: 63.9%
  • Moderate: 35.8%
  • Unhealthy for Sensitive Groups: 0.3%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How was Allentown's air quality in 2020?

Good on a typical day: median AQI 44, with 1 day above AQI 100 out of 366 monitored — the 1st cleanest of 7 years on record for the area.

  • Peak AQI in 2020: 117 (Unhealthy for Sensitive Groups).
  • Fine particulate matter (PM2.5) was the main pollutant on 236 days.
  • Cleanest month: September; worst: December.

Frequently asked questions

What was the average AQI in Allentown in 2020?

EPA's Air Quality System puts Allentown's (Allentown-Bethlehem-Easton, PA-NJ) median daily AQI for 2020 at 44, which is Good. 1 day were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 117.

Which month had the worst air quality in Allentown in 2020?

The cleanest month of 2020 was September (median AQI 39, 0 days above 100) and the worst was December (median 53, 1 day above 100, peak 117).

Was 2020 a good or bad year for Allentown's air?

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 1st cleanest by days above AQI 100 — the best year on record here. 2020's median of 44 is in line with the area's typical annual median of 46.

Allentown month by month in 2020

Allentown air quality month by month, 2020 (Allentown-Bethlehem-Easton, PA-NJ, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January3148094PM2.5
February2952071PM2.5
March3141059PM2.5
April3042058O3
May3140058O3
June3044093O3
July3151080PM2.5
August3146084PM2.5
Septembercleanest3039067PM2.5
October3144058PM2.5
November3054099PM2.5
Decemberworst31531117PM2.5

How 2020 compares

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 1st cleanest by days above AQI 100 — the best year on record here.

2020's median of 44 is in line with 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 33 (PM2.5). 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.