Bad Air Days in Hudson County, New Jersey: 3 a Year

3 bad air days a year

About the middle of monitored US counties. Ranked 381 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (13% particle days).

When the bad days come in Hudson

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

What to buy, and what not to

Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
On the odd bad day, check AirNow and keep windows shut.

Better or worse than it was

In 2000 to 2009 this county averaged 19 bad days a year; in 2016 to 2025, 3. The air has improved. The worst recent year was 2018, with 9 bad days on 365 monitored days.

Date	AQI	Main pollutant
2023-06-07	203	PM2.5
2018-07-01	174	Ozone
2018-07-02	166	Ozone
2023-06-08	159	PM2.5
2023-06-06	155	PM2.5

Most days, not the worst ones

Across 3,653 monitored days from 2016 to 2025, the air in Hudson County rated Good on 61% 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 64.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)56%2,040 days
ozone28%1,027 days
nitrogen dioxide16%584 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	261	101	3	0	41	133
2024	366	261	102	3	1	41	151
2023	365	218	142	5	4	44	203
2022	365	232	131	2	0	44	115
2021	365	216	146	3	0	44	126
2020	366	259	107	0	0	39	90
2019	365	211	154	0	0	47	93
2018	365	190	166	9	2	49	174
2017	365	177	185	3	0	51	115
2016	366	189	175	2	0	49	119
2015	365	195	153	17	1	47	166
2014	365	172	187	6	0	52	150
2013	365	198	165	2	1	47	151
2012	366	174	180	12	0	51	126
2011	365	153	199	13	1	53	156
2010	365	172	180	13	1	52	206

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

Nearby counties on file

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.