Trenton Air Quality in January
Across 2019–2025, Trenton's January air quality had a median AQI of 38 (Good) over 217 monitored days in the Trenton, 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 70.0% of days. The cleanest January on record here was 2021 (median AQI 35, 0 days above 100) and the worst was 2022 (median 52, 0 days above 100, peak AQI 73).
- Good: 68.2%
- Moderate: 31.8%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Extra Protection for Trenton Homes
Air quality in Trenton is moderate (AQI 52), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How is the air in Trenton in January?
Good on a typical day: median AQI 38 across 2019–2025, with 0.0% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓68.2% of January days were Good (AQI 0–50), 31.8% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the January peak was 81.
- ✓Best January: 2021; worst January: 2022.
Frequently asked questions
What is the air quality like in Trenton in January?▾
Across 2019–2025, the median daily AQI in Trenton in January was 38 (Good). 68.2% of days were Good, 31.8% 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 Trenton?▾
A typical January day in Trenton sits in the Good range (median AQI 38), 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 Trenton's January air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 70.0% of January days in Trenton. The highest January AQI recorded in 2019–2025 was 81 (Moderate), in 2022.
Trenton January air quality, year by year
Trenton January air quality by year (Trenton, NJ, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 38 | 0 | 76 | PM2.5 |
| 2020 | 31 | 38 | 0 | 81 | PM2.5 |
| 2021cleanest | 31 | 35 | 0 | 77 | PM2.5 |
| 2022worst | 31 | 52 | 0 | 73 | PM2.5 |
| 2023 | 31 | 39 | 0 | 61 | PM2.5 |
| 2024 | 31 | 36 | 0 | 66 | PM2.5 |
| 2025 | 31 | 38 | 0 | 73 | PM2.5 |
What January air means in Trenton
A typical January day in Trenton sits in the Good range (median AQI 38), 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 38 is below Trenton's whole-year median of 45, making it one of the area's cleaner periods. Nationally, the median January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Trenton runs in line with the national January norm; 0.0% of its January days topped AQI 100 versus 0.7% nationally (about the same).
January is part of Trenton's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Trenton
The latest EPA AirNow observation puts Trenton's AQI at 52 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Trenton air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Trenton, 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.