Bad Air Days in Sequoyah County, Oklahoma: under 1 a Year

under 1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 755 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (86% particle days).

The bad-air season here

Most bad days here fall in March and June. 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 worst days on file

In 2000 to 2009 this county averaged 5 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2025, with 2 bad days on 359 monitored days.

Date	AQI	Main pollutant
2020-06-27	141	PM2.5
2025-03-14	138	PM2.5
2021-03-08	122	PM2.5
2022-03-04	122	PM2.5
2021-06-17	119	Ozone

An ordinary day in Sequoyah

Across 3,619 monitored days from 2016 to 2025, the air in Sequoyah County rated Good on 75% of them, close to the 72% typical of monitored counties, and Moderate on 25%. The median day sat at AQI 41; one day in ten went above 57.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)54%1,963 days
ozone42%1,531 days
nitrogen dioxide3%121 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	359	258	99	2	0	42	138
2024	366	252	114	0	0	44	97
2023	365	227	138	0	0	46	84
2022	364	278	84	2	0	42	122
2021	360	250	108	2	0	41	122
2020	362	304	57	1	0	37	141
2019	361	279	82	0	0	41	67
2018	363	259	104	0	0	41	90
2017	358	298	60	0	0	38	74
2016	361	303	58	0	0	38	74
2015	365	304	61	0	0	36	93
2014	353	277	76	0	0	38	90
2013	365	276	88	1	0	39	105
2012	363	237	110	16	2	44	156
2011	361	232	121	8	0	44	119
2010	281	220	60	1	0	38	129

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

Oklahoma compared

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.