Bad Air Days in Sumner County, Tennessee: 2 a Year

2 bad air days a year

Fewer bad air days than most monitored US counties. Ranked 502 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (11% particle days).

Which months to watch

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

What actually helps 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 Sumner

In 2000 to 2009 this county averaged 39 bad days a year; in 2016 to 2025, 2. The air has improved. The worst recent year was 2023, with 7 bad days on 353 monitored days.

Date	AQI	Main pollutant
2022-07-22	147	Ozone
2018-06-08	133	Ozone
2021-06-17	133	Ozone
2023-06-28	133	Ozone
2024-08-28	133	Ozone

Most days, not the worst ones

Across 3,456 monitored days from 2016 to 2025, the air in Sumner County rated Good on 69% of them, close to the 72% typical of monitored counties, and Moderate on 30%. The median day sat at AQI 43; one day in ten went above 61.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)55%1,912 days
ozone45%1,544 days

Sumner County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	358	248	109	1	0	44	119
2024	358	224	130	4	0	45	133
2023	353	242	104	7	0	45	133
2022	358	249	108	1	0	42	147
2021	357	236	119	2	0	44	133
2020	360	273	86	1	0	41	121
2019	357	240	117	0	0	44	93
2018	346	253	91	2	0	41	133
2017	324	221	103	0	0	44	100
2016	285	209	75	1	0	44	105
2015	284	204	79	1	0	42	112
2014	280	196	83	1	0	43	122
2013	283	191	92	0	0	45	100
2012	245	143	73	29	2	48	179
2011	245	145	88	12	1	47	151
2010	245	135	92	18	1	49	156

*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.