Bad Air Days in Montgomery County, Tennessee: under 1 a Year

under 1 bad air day a year

Rare: among the cleanest-air counties EPA monitors. Ranked 805 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (100% particle days).

When the bad days come in Montgomery

Most bad days here fall in July 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 13 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2020, with 2 bad days on 359 monitored days.

Date	AQI	Main pollutant
2021-07-05	138	PM2.5
2025-07-04	130	PM2.5
2020-07-04	116	PM2.5
2020-06-27	107	PM2.5
2023-07-16	105	PM2.5

The air on a normal day

Across 3,512 monitored days from 2016 to 2025, the air in Montgomery County rated Good on 76% of them, more often than the 72% typical of monitored counties, and Moderate on 23%. The median day sat at AQI 36; one day in ten went above 56.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)100%3,507 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Median AQI	Highest AQI
2025*	358	300	57	1	32	130
2024	361	302	59	0	32	79
2023	351	271	79	1	36	105
2022	359	280	79	0	36	87
2021	359	279	79	1	33	138
2020	359	288	69	2	35	116
2019	362	278	84	0	35	67
2018	354	241	113	0	40	80
2017	341	227	114	0	41	72
2016	308	218	90	0	42	68
2015	356	225	131	0	44	74
2014	344	202	142	0	47	85
2013	355	206	149	0	46	80
2012	62	28	34	0	52	78
2011	62	26	36	0	55	84
2010	62	21	41	0	55	96

*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.