EnviroNearby

Hunterdon County, New Jersey air quality history

Daily Air Quality Index summaries from EPA monitors in Hunterdon, New Jersey, 1980–2025.

74%
Good days in 2025
41
Median daily AQI, 2025
3
Days above 100 in 2025
361
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Hunterdon, New Jersey on 361 days. 268 of those days (74%) were in the Good range, and the median daily AQI was 41. That median is about the same as the typical monitored county in New Jersey (median 40 across 15 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 199 days. Across the years with fuller monitoring, the share of Good days rose: an average of 64% in 1980–1982 versus 70% in 2023–2025.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%1980: Good 114 of 215 days1980: Moderate 32 of 215 days1980: Unhealthy for Sensitive Groups 25 of 215 days1980: Unhealthy 32 of 215 days1980: Very Unhealthy 12 of 215 days19801981: Good 247 of 350 days1981: Moderate 49 of 350 days1981: Unhealthy for Sensitive Groups 28 of 350 days1981: Unhealthy 23 of 350 days1981: Very Unhealthy 3 of 350 days1982: Good 226 of 335 days1982: Moderate 58 of 335 days1982: Unhealthy for Sensitive Groups 28 of 335 days1982: Unhealthy 17 of 335 days1982: Very Unhealthy 6 of 335 days1983: Good 225 of 336 days1983: Moderate 50 of 336 days1983: Unhealthy for Sensitive Groups 30 of 336 days1983: Unhealthy 21 of 336 days1983: Very Unhealthy 10 of 336 days1984: Good 258 of 337 days1984: Moderate 37 of 337 days1984: Unhealthy for Sensitive Groups 20 of 337 days1984: Unhealthy 21 of 337 days1984: Very Unhealthy 1 of 337 days1985: Good 243 of 340 days1985: Moderate 42 of 340 days1985: Unhealthy for Sensitive Groups 30 of 340 days1985: Unhealthy 21 of 340 days1985: Very Unhealthy 4 of 340 days19851986: Good 270 of 341 days1986: Moderate 32 of 341 days1986: Unhealthy for Sensitive Groups 26 of 341 days1986: Unhealthy 13 of 341 days1987: Good 256 of 335 days1987: Moderate 43 of 335 days1987: Unhealthy for Sensitive Groups 18 of 335 days1987: Unhealthy 16 of 335 days1987: Very Unhealthy 2 of 335 days1988: Good 246 of 328 days1988: Moderate 26 of 328 days1988: Unhealthy for Sensitive Groups 22 of 328 days1988: Unhealthy 19 of 328 days1988: Very Unhealthy 15 of 328 days1989: Good 260 of 346 days1989: Moderate 42 of 346 days1989: Unhealthy for Sensitive Groups 25 of 346 days1989: Unhealthy 16 of 346 days1989: Very Unhealthy 3 of 346 days1990: Good 238 of 315 days1990: Moderate 40 of 315 days1990: Unhealthy for Sensitive Groups 13 of 315 days1990: Unhealthy 16 of 315 days1990: Very Unhealthy 8 of 315 days19901991: Good 249 of 348 days1991: Moderate 50 of 348 days1991: Unhealthy for Sensitive Groups 26 of 348 days1991: Unhealthy 18 of 348 days1991: Very Unhealthy 5 of 348 days1992: Good 288 of 338 days1992: Moderate 27 of 338 days1992: Unhealthy for Sensitive Groups 16 of 338 days1992: Unhealthy 5 of 338 days1992: Very Unhealthy 2 of 338 days1993: Good 246 of 336 days1993: Moderate 46 of 336 days1993: Unhealthy for Sensitive Groups 32 of 336 days1993: Unhealthy 12 of 336 days1994: Good 281 of 357 days1994: Moderate 44 of 357 days1994: Unhealthy for Sensitive Groups 27 of 357 days1994: Unhealthy 5 of 357 days1995: Good 281 of 364 days1995: Moderate 43 of 364 days1995: Unhealthy for Sensitive Groups 26 of 364 days1995: Unhealthy 13 of 364 days1995: Very Unhealthy 1 of 364 days19951996: Good 291 of 359 days1996: Moderate 36 of 359 days1996: Unhealthy for Sensitive Groups 27 of 359 days1996: Unhealthy 5 of 359 days1997: Good 288 of 364 days1997: Moderate 38 of 364 days1997: Unhealthy for Sensitive Groups 21 of 364 days1997: Unhealthy 14 of 364 days1997: Very Unhealthy 3 of 364 days1998: Good 261 of 362 days1998: Moderate 53 of 362 days1998: Unhealthy for Sensitive Groups 31 of 362 days1998: Unhealthy 17 of 362 days1999: Good 280 of 364 days1999: Moderate 47 of 364 days1999: Unhealthy for Sensitive Groups 14 of 364 days1999: Unhealthy 19 of 364 days1999: Very Unhealthy 4 of 364 days2000: Good 300 of 366 days2000: Moderate 41 of 366 days2000: Unhealthy for Sensitive Groups 17 of 366 days2000: Unhealthy 7 of 366 days2000: Very Unhealthy 1 of 366 days20002001: Good 264 of 357 days2001: Moderate 53 of 357 days2001: Unhealthy for Sensitive Groups 30 of 357 days2001: Unhealthy 9 of 357 days2001: Very Unhealthy 1 of 357 days2002: Good 272 of 361 days2002: Moderate 43 of 361 days2002: Unhealthy for Sensitive Groups 28 of 361 days2002: Unhealthy 16 of 361 days2002: Very Unhealthy 2 of 361 days2003: Good 286 of 359 days2003: Moderate 54 of 359 days2003: Unhealthy for Sensitive Groups 13 of 359 days2003: Unhealthy 4 of 359 days2003: Very Unhealthy 2 of 359 days2004: Good 289 of 361 days2004: Moderate 52 of 361 days2004: Unhealthy for Sensitive Groups 16 of 361 days2004: Unhealthy 4 of 361 days2005: Good 277 of 363 days2005: Moderate 52 of 363 days2005: Unhealthy for Sensitive Groups 25 of 363 days2005: Unhealthy 9 of 363 days20052006: Good 220 of 353 days2006: Moderate 111 of 353 days2006: Unhealthy for Sensitive Groups 18 of 353 days2006: Unhealthy 4 of 353 days2007: Good 187 of 353 days2007: Moderate 137 of 353 days2007: Unhealthy for Sensitive Groups 22 of 353 days2007: Unhealthy 7 of 353 days2008: Good 193 of 366 days2008: Moderate 153 of 366 days2008: Unhealthy for Sensitive Groups 17 of 366 days2008: Unhealthy 3 of 366 days2009: Good 208 of 364 days2009: Moderate 153 of 364 days2009: Unhealthy for Sensitive Groups 3 of 364 days2010: Good 199 of 364 days2010: Moderate 141 of 364 days2010: Unhealthy for Sensitive Groups 22 of 364 days2010: Unhealthy 2 of 364 days20102011: Good 200 of 362 days2011: Moderate 147 of 362 days2011: Unhealthy for Sensitive Groups 13 of 362 days2011: Unhealthy 2 of 362 days2012: Good 203 of 363 days2012: Moderate 150 of 363 days2012: Unhealthy for Sensitive Groups 10 of 363 days2013: Good 246 of 365 days2013: Moderate 115 of 365 days2013: Unhealthy for Sensitive Groups 4 of 365 days2014: Good 245 of 363 days2014: Moderate 116 of 363 days2014: Unhealthy for Sensitive Groups 2 of 363 days2015: Good 280 of 363 days2015: Moderate 79 of 363 days2015: Unhealthy for Sensitive Groups 4 of 363 days20152016: Good 234 of 355 days2016: Moderate 114 of 355 days2016: Unhealthy for Sensitive Groups 6 of 355 days2016: Unhealthy 1 of 355 days2017: Good 237 of 364 days2017: Moderate 123 of 364 days2017: Unhealthy for Sensitive Groups 4 of 364 days2018: Good 236 of 352 days2018: Moderate 111 of 352 days2018: Unhealthy for Sensitive Groups 3 of 352 days2018: Unhealthy 2 of 352 days2019: Good 256 of 362 days2019: Moderate 105 of 362 days2019: Unhealthy for Sensitive Groups 1 of 362 days2020: Good 265 of 364 days2020: Moderate 99 of 364 days20202021: Good 249 of 364 days2021: Moderate 115 of 364 days2022: Good 263 of 364 days2022: Moderate 101 of 364 days2023: Good 233 of 364 days2023: Moderate 121 of 364 days2023: Unhealthy for Sensitive Groups 6 of 364 days2023: Unhealthy 3 of 364 days2023: Very Unhealthy 1 of 364 days2024: Good 266 of 365 days2024: Moderate 99 of 365 days2025: Good 268 of 361 days2025: Moderate 90 of 361 days2025: Unhealthy for Sensitive Groups 3 of 361 days2025
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501001502001980: 90th percentile AQI 1871981: 90th percentile AQI 1291982: 90th percentile AQI 1331983: 90th percentile AQI 1501984: 90th percentile AQI 1221985: 90th percentile AQI 1291986: 90th percentile AQI 1051987: 90th percentile AQI 1121988: 90th percentile AQI 1511989: 90th percentile AQI 1221990: 90th percentile AQI 1191991: 90th percentile AQI 1261992: 90th percentile AQI 841993: 90th percentile AQI 1151994: 90th percentile AQI 931995: 90th percentile AQI 1051996: 90th percentile AQI 901997: 90th percentile AQI 1011998: 90th percentile AQI 1191999: 90th percentile AQI 1052000: 90th percentile AQI 802001: 90th percentile AQI 1082002: 90th percentile AQI 1152003: 90th percentile AQI 842004: 90th percentile AQI 802005: 90th percentile AQI 1002006: 90th percentile AQI 872007: 90th percentile AQI 952008: 90th percentile AQI 872009: 90th percentile AQI 672010: 90th percentile AQI 902011: 90th percentile AQI 692012: 90th percentile AQI 772013: 90th percentile AQI 642014: 90th percentile AQI 642015: 90th percentile AQI 612016: 90th percentile AQI 672017: 90th percentile AQI 632018: 90th percentile AQI 652019: 90th percentile AQI 622020: 90th percentile AQI 572021: 90th percentile AQI 612022: 90th percentile AQI 602023: 90th percentile AQI 642024: 90th percentile AQI 612025: 90th percentile AQI 611980: Median AQI 491981: Median AQI 401982: Median AQI 411983: Median AQI 381984: Median AQI 311985: Median AQI 341986: Median AQI 301987: Median AQI 311988: Median AQI 351989: Median AQI 331990: Median AQI 351991: Median AQI 351992: Median AQI 291993: Median AQI 351994: Median AQI 351995: Median AQI 321996: Median AQI 321997: Median AQI 361998: Median AQI 361999: Median AQI 342000: Median AQI 342001: Median AQI 362002: Median AQI 352003: Median AQI 332004: Median AQI 352005: Median AQI 372006: Median AQI 432007: Median AQI 482008: Median AQI 482009: Median AQI 462010: Median AQI 472011: Median AQI 482012: Median AQI 482013: Median AQI 422014: Median AQI 422015: Median AQI 392016: Median AQI 432017: Median AQI 442018: Median AQI 432019: Median AQI 432020: Median AQI 412021: Median AQI 432022: Median AQI 422023: Median AQI 442024: Median AQI 412025: Median AQI 411980198519901995200020052010201520202025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2025

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Ozone19955%
Fine particles (PM2.5)16245%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253612689030004161122Ozone
20243652669900004161100Ozone
202336423312163104464262Ozone
20223642631010000426093Ozone
20213642491150000436197PM2.5
2020364265990000415787PM2.5
201936225610510004362108PM2.5
201835223611132004365179PM2.5
201736423712340004463122PM2.5
201635523411461004367156Ozone
20153632807940003961115Ozone
201436324511620004264105Ozone
201336524611540004264119Ozone
2012363203150100004877143Ozone
2011362200147132004869156PM2.5
2010364199141222004790169Ozone
200936420815330004667136PM2.5
2008366193153173004887164PM2.5
2007353187137227004895182Ozone
2006353220111184004387169Ozone
2005363277522590037100187Ozone
200436128952164003580182Ozone
200335928654134203384210Ozone
20023612724328162035115210Ozone
2001357264533091036108207Ozone
200036630041177103480201Ozone
19993642804714194034105210Ozone
19983622615331170036119185Ozone
19973642883821143036101202Ozone
199635929136275003290169Ozone
19953642814326131032105201Ozone
199435728144275003593185Ozone
19933362464632120035115200Ozone
199233828827165202984201Ozone
19913482495026185035126206Ozone
19903152384013168035119227Ozone
19893462604225163033122207Ozone
198832824626221915035151251Ozone
19873352564318162031112217Ozone
19863412703226130030105197Ozone
19853402434230214034129223Ozone
19843372583720211031122201Ozone
198333622550302110038150237Ozone
19823352265828176041133246Ozone
19813502474928233040129210Ozone
198021511432253212049187217Ozone

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

Counties in New Jersey with a similar median AQI in 2025

All monitored counties in New Jersey

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem