Bad Air Days in Erie County, New York: 3 a Year

3 bad air days a year

About the middle of monitored US counties. Ranked 335 of 996 monitored counties, where 1 is worst.

What makes them bad: a mix of particles and ozone (59% particle days).

The bad-air season here

Most bad days here fall in June and July and May 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.

The record for Erie

In 2000 to 2009 this county averaged 20 bad days a year; in 2016 to 2025, 3. The air has improved. The worst recent year was 2025, with 11 bad days on 365 monitored days.

Date	AQI	Main pollutant
2023-06-07	176	PM2.5
2023-06-30	171	PM2.5
2023-06-28	168	PM2.5
2020-07-04	157	PM2.5
2020-07-05	153	PM2.5

The air on a normal day

Across 3,653 monitored days from 2016 to 2025, the air in Erie County rated Good on 63% of them, less often than the 72% typical of monitored counties, and Moderate on 36%. The median day sat at AQI 45; one day in ten went above 63.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)64%2,320 days
ozone35%1,276 days
nitrogen dioxide1%54 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	233	121	11	0	44	140
2024	366	234	131	1	0	43	105
2023	365	198	159	8	3	48	176
2022	365	238	125	2	0	44	150
2021	365	225	139	1	0	46	101
2020	366	278	86	2	2	41	157
2019	365	262	103	0	0	43	93
2018	365	220	143	2	0	45	112
2017	365	205	159	1	0	48	119
2016	366	210	150	6	0	47	136
2015	365	156	205	4	0	52	119
2014	365	158	206	1	0	52	101
2013	365	187	174	4	0	50	122
2012	366	156	196	14	1	52	151
2011	365	153	210	2	0	52	115
2010	365	149	209	7	0	53	122

*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.