Allentown Air Quality in Spring

Across 2019–2025, Allentown's spring (March–May) air quality had a median AQI of 44 (Good) over 644 monitored days in the Allentown-Bethlehem-Easton, PA-NJ area. 0.3% of spring days (2 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 62.3% of days. The cleanest spring on record here was 2020 (median AQI 41, 0 days above 100) and the worst was 2021 (median 46, 2 days above 100, peak AQI 105).

44
Median AQI
Good
0.3%
Days above AQI 100
2 of 644 days
59
90th percentile AQI
worst 1 day in 10
105
Peak AQI
Unhealthy for Sensitive Groups
O3
Main pollutant
62.3% of days
70.8%
Good days
456 of 644
  • Good: 70.8%
  • Moderate: 28.9%
  • Unhealthy for Sensitive Groups: 0.3%
  • 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.

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QUICK ANSWER

How is the air in Allentown in spring?

Good on a typical day: median AQI 44 across 2019–2025, with 0.3% of spring days above AQI 100. Ground-level ozone is the main driver.

  • 70.8% of spring days were Good (AQI 0–50), 28.9% Moderate (51–100).
  • 2 days of 644 reached AQI 101+; the spring peak was 105.
  • Cleanest month: March; worst month: May.

Frequently asked questions

What is the air quality like in Allentown in spring?

Across 2019–2025, the median daily AQI in Allentown in spring was 44 (Good). 70.8% of days were Good, 28.9% Moderate, and 0.3% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.

Is spring a good time for outdoor exercise in Allentown?

A typical spring day in Allentown sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of spring days reached AQI 101+ in 2019–2025.

Which pollutant causes Allentown's spring air quality problems?

Ground-level ozone set the daily AQI on 62.3% of spring days in Allentown. The highest spring AQI recorded in 2019–2025 was 105 (Unhealthy for Sensitive Groups), in 2021.

Allentown spring air quality, year by year

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

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20199245082O3
2020cleanest9241059O3
2021worst92462105O3
20229244078O3
202392470100O3
20249241087O3
202592430100O3

What spring air means in Allentown

A typical spring day in Allentown sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of spring days reached AQI 101+ in 2019–2025.

Spring's median AQI of 44 is in line with Allentown's whole-year median of 46, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Spring AQI across every EPA metro area (307,196 metro-days, 2019–2025) is 43, so Allentown runs in line with the national Spring norm; 0.3% of its Spring days topped AQI 100 versus 0.8% nationally (about the same).

Within the season, March is the cleanest month (median AQI 43, 0.0% of days above 100) and May the worst (median 43, 0.9% above 100).

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 season 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.