Bad Air Days in Bergen County, New Jersey: 7 a Year

7 bad air days a year

More bad air days than three quarters of monitored counties. Ranked 137 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (10% particle days).

The bad-air season here

Most bad days here fall in July and June and August. Averaged over 2016 to 2025.

What to buy, and what not to

Ozone drives many bad days here. Purifiers and filters do not remove ozone, so do not buy one for that. Ozone peaks on hot afternoons: exercise outside in the morning.

Better or worse than it was

In 2000 to 2009 this county averaged 22 bad days a year; in 2016 to 2025, 7. The air has improved. The worst recent year was 2018, with 14 bad days on 365 monitored days.

Date	AQI	Main pollutant
2023-06-07	197	PM2.5
2018-07-02	164	Ozone
2023-06-08	164	PM2.5
2018-07-01	161	Ozone
2023-06-06	159	PM2.5

An ordinary day in Bergen

Across 3,649 monitored days from 2016 to 2025, the air in Bergen County rated Good on 59% of them, less often than the 72% typical of monitored counties, and Moderate on 39%. The median day sat at AQI 45; one day in ten went above 67.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)55%1,992 days
ozone30%1,088 days
nitrogen dioxide15%564 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	363	258	101	4	0	40	136
2024	366	267	89	10	1	40	156
2023	365	204	152	9	4	48	197
2022	365	259	106	0	0	42	90
2021	365	230	126	9	0	43	147
2020	364	228	133	3	0	43	119
2019	365	149	211	5	0	53	150
2018	365	153	198	14	2	53	164
2017	365	209	149	7	0	45	140
2016	366	197	159	10	1	47	151
2015	365	144	209	12	0	54	133
2014	318	248	64	6	0	41	133
2013	283	209	67	7	0	39	119
2012	251	188	55	8	0	38	133
2011	320	234	73	13	3	39	174
2010	365	268	81	16	0	39	150

*2025 may be a partial year in EPA's file.

Elsewhere in New Jersey

How this is counted

A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day, and on why a purifier does not touch ozone in smoke vs ozone.