Allentown Air Quality in October
Across 2019–2025, Allentown's October air quality had a median AQI of 37 (Good) over 217 monitored days in the Allentown-Bethlehem-Easton, PA-NJ area. 0.0% of October days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 59.9% of days. The cleanest October on record here was 2025 (median AQI 31, 0 days above 100) and the worst was 2021 (median 47, 0 days above 100, peak AQI 66).
- Good: 73.3%
- Moderate: 26.7%
- Unhealthy for Sensitive Groups: 0.0%
- 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 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 October?
Good on a typical day: median AQI 37 across 2019–2025, with 0.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓73.3% of October days were Good (AQI 0–50), 26.7% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the October peak was 71.
- ✓Best October: 2025; worst October: 2021.
Frequently asked questions
What is the air quality like in Allentown in October?▾
Across 2019–2025, the median daily AQI in Allentown in October was 37 (Good). 73.3% of days were Good, 26.7% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Allentown?▾
A typical October day in Allentown sits in the Good range (median AQI 37), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
Which pollutant causes Allentown's October air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 59.9% of October days in Allentown. The highest October AQI recorded in 2019–2025 was 71 (Moderate), in 2021.
Allentown October air quality, year by year
Allentown October 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 | 31 | 34 | 0 | 60 | PM2.5 |
| 2020 | 31 | 44 | 0 | 58 | PM2.5 |
| 2021worst | 31 | 47 | 0 | 66 | PM2.5 |
| 2022 | 31 | 43 | 0 | 68 | PM2.5 |
| 2023 | 31 | 33 | 0 | 59 | PM2.5 |
| 2024 | 31 | 36 | 0 | 64 | O3 |
| 2025cleanest | 31 | 31 | 0 | 71 | O3 |
What October air means in Allentown
A typical October day in Allentown sits in the Good range (median AQI 37), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
October's median AQI of 37 is below Allentown's whole-year median of 46, making it one of the area's cleaner periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Allentown runs in line with the national October norm; 0.0% of its October days topped AQI 100 versus 1.3% nationally (below average).
October is part of Allentown's fall season (September, October, November); the fall page pools all three months.
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 month 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.