Bad Air Days in Lenoir County, North Carolina: under 1 a Year

under 1 bad air days a year

Rare: among the cleanest-air counties EPA monitors. Ranked 850 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 Lenoir

Most bad days here fall in June and July. 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 Lenoir

In 2000 to 2009 this county averaged 16 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2022, with 1 bad day on 241 monitored days.

Date	AQI	Main pollutant
2018-06-06	108	Ozone
2022-06-22	108	Ozone
2023-07-18	105	Ozone
2023-04-20	100	Ozone
2016-04-19	97	Ozone

The air on a normal day

Across 2,713 monitored days from 2016 to 2025, the air in Lenoir County rated Good on 92% of them, more often than the 72% typical of monitored counties, and Moderate on 8%. The median day sat at AQI 36; one day in ten went above 49.

The pollutant setting the AQI on an ordinary day here:

ozone87%2,349 days
coarse dust (PM10)13%364 days

Lenoir County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	245	239	6	0	0	35	71
2024	308	295	13	0	0	34	77
2023	305	272	32	1	0	39	105
2022	241	217	23	1	0	39	108
2021	306	284	22	0	0	34	97
2020	296	290	6	0	0	32	58
2019	237	205	32	0	0	42	87
2018	278	249	28	1	0	36	108
2017	304	279	25	0	0	35	90
2016	193	171	22	0	0	40	97
2015	209	185	24	0	0	41	80
2014	214	177	37	0	0	40	93
2013	262	217	45	0	0	38	100
2012	276	218	57	1	0	41	143
2011	259	164	90	5	1	45	162
2010	260	159	99	2	0	47	140

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

North Carolina 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, and on why a purifier does not touch ozone in smoke vs ozone.