Atlantic City Best & Worst AQI Days: Air Quality Guide

The worst air quality day on record for Atlantic City (Atlantic City-Hammonton, NJ area) was June 8, 2023, when the daily AQI reached 265 (Very Unhealthy), set by fine particulate matter (PM2.5), in wildfire smoke season. Across 2,547 monitored days in 2019–2025, 3 of the 10 worst days were Unhealthy (AQI 151+) or worse; 7 of the 10 were driven by fine particulate matter (PM2.5) and 3 by ground-level ozone, and 5 of them fell in 2023. The cleanest day was May 27, 2020 at AQI 2 (Good); the 10 best days span 4 different years.

265
Worst day AQI
2023-06-08
2
Best day AQI
2020-05-27
3
Top-10 days at 151+
Unhealthy or worse
2,547
Days monitored
2019–2025

Reduce Indoor Ozone in Atlantic City

Today's main pollutant in Atlantic City is ground-level ozone (AQI 31). 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.

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QUICK ANSWER

When were Atlantic City's worst and best air quality days?

Worst: June 8, 2023, AQI 265 (Very Unhealthy, PM2.5). Best: May 27, 2020, AQI 2 (Good). Based on 2,547 EPA-monitored days in the Atlantic City-Hammonton, NJ area, 2019–2025.

  • 3 of the 10 worst days were Unhealthy (AQI 151+) or worse; the 10th-worst was AQI 99 (Moderate).
  • Fine particulate matter (PM2.5) drove 7 of the 10 worst days.
  • 2023 accounts for 5 of the 10 worst days.

Frequently asked questions

What was the worst air quality day in Atlantic City?

June 8, 2023: the Atlantic City-Hammonton, NJ area's daily AQI hit 265 (Very Unhealthy), driven by fine particulate matter (PM2.5), in wildfire smoke season. That is the highest of 2,547 monitored days in 2019–2025.

What was the best air quality day in Atlantic City?

May 27, 2020, with a daily AQI of 2 (Good). The daily AQI is the highest reading from any monitor in the area, so even the cleanest day reflects the area's worst monitor.

What was Atlantic City's worst air quality day in 2025?

June 23, 2025, AQI 105 (Unhealthy for Sensitive Groups), set by ground-level ozone, in peak ozone season.

Which pollutant causes Atlantic City's worst air days?

Fine particulate matter (PM2.5) set the AQI on 7 of the 10 worst days; ground-level ozone on 3. The tables above list the defining pollutant for every day.

Atlantic City's 10 worst air quality days, 2019–2025

Highest daily AQI recorded for the Atlantic City-Hammonton, NJ area (EPA AQS). The daily AQI is the highest reading from any monitor in the area that day.

#DateAQICategoryDefining pollutant
1 (2023 page)265Very UnhealthyPM2.5fine particulate matter (PM2.5), in wildfire smoke season
2 (2023 page)199UnhealthyPM2.5fine particulate matter (PM2.5), in wildfire smoke season
3 (2022 page)185UnhealthyPM2.5fine particulate matter (PM2.5), in wildfire smoke season
4 (2023 page)144Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5), in wildfire smoke season
5 (2023 page)113Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5), in wildfire smoke season
6 (2023 page)107Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5), in wildfire smoke season
7 (2025 page)105Unhealthy for Sensitive GroupsO3ground-level ozone, in peak ozone season
8 (2019 page)105Unhealthy for Sensitive GroupsO3ground-level ozone, in peak ozone season
9 (2019 page)100ModerateO3ground-level ozone, in peak ozone season
10 (2025 page)99ModeratePM2.5fine particulate matter (PM2.5)

Worst day of each year in Atlantic City

The single highest-AQI day in each year on record. Click a year for its full month-by-month statistics.

YearWorst dayAQICategoryDefining pollutant
2019105Unhealthy for Sensitive GroupsO3ground-level ozone, in peak ozone season
202090ModerateO3ground-level ozone, in peak ozone season
202196ModeratePM2.5fine particulate matter (PM2.5)
2022185UnhealthyPM2.5fine particulate matter (PM2.5), in wildfire smoke season
2023265Very UnhealthyPM2.5fine particulate matter (PM2.5), in wildfire smoke season
202497ModeratePM2.5fine particulate matter (PM2.5)
2025105Unhealthy for Sensitive GroupsO3ground-level ozone, in peak ozone season

Atlantic City's 10 best air quality days, 2019–2025

Lowest daily AQI recorded for the Atlantic City-Hammonton, NJ area. Ties are listed most recent first.

#DateAQICategoryDefining pollutant
1 (2020 page)2GoodPM2.5fine particulate matter (PM2.5)
2 (2024 page)5GoodPM2.5fine particulate matter (PM2.5)
3 (2022 page)8GoodPM2.5fine particulate matter (PM2.5)
4 (2020 page)8GoodPM2.5fine particulate matter (PM2.5)
5 (2020 page)9GoodPM2.5fine particulate matter (PM2.5)
6 (2022 page)10GoodPM2.5fine particulate matter (PM2.5)
7 (2022 page)11GoodPM2.5fine particulate matter (PM2.5)
8 (2020 page)12GoodO3ground-level ozone
9 (2025 page)13GoodPM2.5fine particulate matter (PM2.5)
10 (2025 page)13GoodPM2.5fine particulate matter (PM2.5)

Right now in Atlantic City

The latest EPA AirNow observation puts Atlantic City's AQI at 31 (O3). The days above are historical records, not today's reading.

View current Atlantic City air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Atlantic City-Hammonton, 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.