Bad Air Days in Oswego County, New York: under 1 a Year

under 1 bad air days a year

Rare: among the cleanest-air counties EPA monitors. Ranked 880 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (0% particle days).

When the bad days come in Oswego

Most bad days here fall in May. Averaged over 2016 to 2025.

Is a purifier worth it here?

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 Oswego

In 2000 to 2009 this county averaged 12 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2016, with 1 bad day on 283 monitored days.

Date	AQI	Main pollutant
2018-05-26	112	Ozone
2023-05-12	105	Ozone
2016-05-25	101	Ozone
2016-05-26	100	Ozone
2023-04-14	100	Ozone

Most days, not the worst ones

Across 3,430 monitored days from 2016 to 2025, the air in Oswego County rated Good on 96% of them, more often than the 72% typical of monitored counties, and Moderate on 4%. The median day sat at AQI 33; one day in ten went above 45.

The pollutant setting the AQI on an ordinary day here:

ozone100%3,430 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Median AQI	Highest AQI
2025*	328	319	9	0	34	80
2024	359	353	6	0	32	61
2023	356	341	14	1	33	105
2022	354	349	5	0	32	58
2021	360	337	23	0	34	97
2020	359	349	10	0	33	58
2019	321	316	5	0	34	67
2018	350	324	25	1	32	112
2017	360	346	14	0	34	87
2016	283	261	21	1	34	101
2015	286	277	8	1	32	115
2014	362	356	6	0	31	97
2013	359	345	14	0	33	84
2012	347	314	29	4	34	122
2011	339	316	21	2	34	126
2010	354	311	39	4	34	115

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

Elsewhere in New York

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.