What Is the Air Quality in Hunterdon, New Jersey?
Hunterdon, New Jersey has an Air Quality Grade of C (fair) with a 5-year median AQI of 43. The dominant pollutant is Ground-Level Ozone, and air quality has been stable over the past decade.
Hunterdon, New Jersey Air Quality Snapshot
| Air Quality Grade | C63/100 |
| 5-Year Median AQI | 43 (Good) |
| Most Recent Median AQI (2023) | 44 (Good) |
| Dominant Pollutant | Ground-Level Ozone |
| 10-Year Trend | Stable (+0.18 AQI/yr) |
| Unhealthy Days (last 5 yr) | 11 |
| National Rank (cleanest = #1) | #633 of 1,020 (62th most polluted percentile) |
| New Jersey Rank | #9 of 16 |
What Does the C Grade Mean?
Hunterdon, New Jersey earns a C — air quality is fair, but not great. With a 5-year median AQI of 43, the city sees a meaningful number of "Moderate" days each year, when the EPA flags air as a concern for unusually sensitive people.
Hunterdon, New Jersey's 5-year median AQI of 43 is right around the national average of 41 across the 1,020 monitored U.S. cities tracked here. Within New Jersey, Hunterdon, New Jersey's air quality is roughly typical for the state, where the average city posts a 5-year median AQI of 42.
For context within New Jersey: Hudson, New Jersey currently holds the state's cleanest grade (B, AQI 44), while Essex, New Jersey sits at the bottom (C, AQI 45).
What's in Hunterdon, New Jersey's Air?
The dominant pollutant in Hunterdon, New Jersey is Ground-Level Ozone. Ground-level ozone forms when sunlight reacts with vehicle exhaust and industrial emissions. It is worst on hot, sunny, stagnant summer days. Ozone irritates the lungs, triggers asthma attacks, and reduces lung function — even healthy adults can feel chest tightness and shortness of breath after exercising in elevated ozone.
Days by Dominant Pollutant (2023)
| Pollutant | Days as Dominant | Share of Year |
|---|---|---|
| Ground-Level Ozone | 184 | 51% |
| Fine Particulate Matter (PM2.5) | 180 | 49% |
Is the Air Getting Better or Worse?
Air quality in Hunterdon, New Jersey has held roughly steady over the past decade, with year-to-year shifts in median AQI of less than half a point. That stability makes the city's long-run grade a reliable signal of what residents can expect day-to-day.
In 2014, Hunterdon, New Jersey posted a median AQI of 42. By 2023 that figure was 44 — a rise of 2 AQI points dirtier across 10 years of EPA records.
Year-by-Year AQI in Hunterdon, New Jersey
| Year | Median AQI | Good Days | Unhealthy Days | Dominant Pollutant |
|---|---|---|---|---|
| 2014 | 42 | 245 | 2 | Ozone |
| 2015 | 39 | 280 | 4 | Ozone |
| 2016 | 43 | 234 | 7 | Ozone |
| 2017 | 44 | 237 | 4 | PM2.5 |
| 2018 | 43 | 236 | 5 | PM2.5 |
| 2019 | 43 | 256 | 1 | PM2.5 |
| 2020 | 41 | 265 | 0 | PM2.5 |
| 2021 | 43 | 249 | 0 | PM2.5 |
| 2022 | 42 | 263 | 0 | Ozone |
| 2023 | 44 | 233 | 10 | Ozone |
Health Context for Hunterdon, New Jersey
Across the past five years, this area has logged just 11 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 2 days per year, or roughly one every other month. That is a low count by national standards.
Healthy adults can continue normal outdoor activity in most weather, but should pay attention to AQI alerts during the worst pollution windows. People with asthma, heart disease, or pregnancy should reduce prolonged or intense outdoor exertion on flagged days, and consider running an indoor HEPA air cleaner during peak season. Because ozone peaks in the afternoon on hot sunny days, plan outdoor exercise for early morning or after sunset on bad-air days.
How This Grade Is Calculated
The AirHistory Air Quality Grade combines four signals: the 5-year median AQI (40% of the score), the 10-year trend direction (30%), the count of unhealthy days per year (20%), and the dominant pollutant type (10%). All four come directly from the EPA Air Quality System (AQS), which aggregates readings from federally certified monitors. Read the full methodology.
Hunterdon, New Jersey has an Air Quality Grade of C (fair) with a 5-year median AQI of 43. The dominant pollutant is Ground-Level Ozone, and air quality has been stable over the past decade.
This answer pulls from the EPA Air Quality System (AQS), the authoritative federal source for U.S. air quality and pollution monitoring. The headline number above is the direct answer; what follows is the additional context most readers need to use the answer for a real decision rather than just a fact lookup.
For readers turning this answer into action: cross-reference against the underlying the EPA Air Quality System (AQS) record before acting on time-sensitive decisions. The site renders the data as it was published; subsequent revisions can shift the picture, and the live federal data is always the authoritative current reference.
Source: EPA Outdoor Air Quality Data, 2026.