Allentown Air Quality in Summer
Across 2019–2025, Allentown's summer (June–August) air quality had a median AQI of 51 (Moderate) over 644 monitored days in the Allentown-Bethlehem-Easton, PA-NJ area. 2.5% of summer days (16 of 644) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 51.9% of days. The cleanest summer on record here was 2020 (median AQI 48, 0 days above 100) and the worst was 2023 (median 54, 7 days above 100, peak AQI 368).
- Good: 47.0%
- Moderate: 50.5%
- Unhealthy for Sensitive Groups: 1.6%
- Unhealthy or worse: 0.9%
Reduce Indoor Ozone in Allentown
Today's main pollutant in Allentown is ground-level ozone (AQI 28). 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 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Allentown in summer?
Moderate on a typical day: median AQI 51 across 2019–2025, with 2.5% of summer days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓47.0% of summer days were Good (AQI 0–50), 50.5% Moderate (51–100).
- ✓16 days of 644 reached AQI 101+; the summer peak was 368.
- ✓Cleanest month: August; worst month: June.
Frequently asked questions
What is the air quality like in Allentown in summer?▾
Across 2019–2025, the median daily AQI in Allentown in summer was 51 (Moderate). 47.0% of days were Good, 50.5% Moderate, and 2.5% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Allentown?▾
A typical summer day in Allentown is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 40 of summer days (2.5%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Allentown's summer air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 51.9% of summer days in Allentown. The highest summer AQI recorded in 2019–2025 was 368 (Hazardous), in 2023.
Allentown summer air quality, year by year
Allentown summer air quality by year (Allentown-Bethlehem-Easton, PA-NJ, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 92 | 51 | 1 | 101 | PM2.5 |
| 2020cleanest | 92 | 48 | 0 | 93 | PM2.5 |
| 2021 | 92 | 56 | 2 | 154 | PM2.5 |
| 2022 | 92 | 52 | 0 | 93 | O3 |
| 2023worst | 92 | 54 | 7 | 368 | PM2.5 |
| 2024 | 92 | 52 | 3 | 119 | O3 |
| 2025 | 92 | 49 | 3 | 122 | O3 |
What summer air means in Allentown
A typical summer day in Allentown is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 40 of summer days (2.5%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Summer's median AQI of 51 is above Allentown's whole-year median of 46, making it one of the area's dirtier periods. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Allentown runs above the national Summer norm; 2.5% of its Summer days topped AQI 100 versus 3.6% nationally (below average).
Within the season, August is the cleanest month (median AQI 49, 0.9% of days above 100) and June the worst (median 50, 5.3% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Allentown
The latest EPA AirNow observation puts Allentown's AQI at 28 (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.