Allentown Air Quality in January
Across 2019–2025, Allentown's January air quality had a median AQI of 46 (Good) over 217 monitored days in the Allentown-Bethlehem-Easton, PA-NJ area. 0.0% of January days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 75.6% of days. The cleanest January on record here was 2024 (median AQI 32, 0 days above 100) and the worst was 2022 (median 52, 0 days above 100, peak AQI 88).
- Good: 55.3%
- Moderate: 44.7%
- 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
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Allentown in January?
Good on a typical day: median AQI 46 across 2019–2025, with 0.0% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓55.3% of January days were Good (AQI 0–50), 44.7% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the January peak was 94.
- ✓Best January: 2024; worst January: 2022.
Frequently asked questions
What is the air quality like in Allentown in January?▾
Across 2019–2025, the median daily AQI in Allentown in January was 46 (Good). 55.3% of days were Good, 44.7% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is January a good time for outdoor exercise in Allentown?▾
A typical January day in Allentown sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.
Which pollutant causes Allentown's January air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 75.6% of January days in Allentown. The highest January AQI recorded in 2019–2025 was 94 (Moderate), in 2022.
Allentown January air quality, year by year
Allentown January 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 | 48 | 0 | 77 | PM2.5 |
| 2020 | 31 | 48 | 0 | 94 | PM2.5 |
| 2021 | 31 | 46 | 0 | 91 | PM2.5 |
| 2022worst | 31 | 52 | 0 | 88 | PM2.5 |
| 2023 | 31 | 51 | 0 | 70 | PM2.5 |
| 2024cleanest | 31 | 32 | 0 | 69 | PM2.5 |
| 2025 | 31 | 39 | 0 | 87 | PM2.5 |
What January air means in Allentown
A typical January day in Allentown sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.
January's median AQI of 46 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 January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Allentown runs above the national January norm; 0.0% of its January days topped AQI 100 versus 0.7% nationally (about the same).
January is part of Allentown's winter season (December, January, February); the winter 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.