Bad Air Days in Lebanon County, Pennsylvania: 3 a Year

3 bad air days a year

About the middle of monitored US counties. Ranked 323 of 996 monitored counties, where 1 is worst.

What makes them bad: a mix of particles and ozone (55% particle days).

Which months to watch

Most bad days here fall in June and July and May. 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 record for Lebanon

The worst recent year was 2023, with 10 bad days on 365 monitored days.

Date	AQI	Main pollutant
2023-06-07	265	PM2.5
2023-06-08	232	PM2.5
2023-06-29	173	PM2.5
2023-06-30	162	PM2.5
2023-06-06	155	PM2.5

An ordinary day in Lebanon

Across 3,451 monitored days from 2016 to 2025, the air in Lebanon County rated Good on 54% of them, less often than the 72% typical of monitored counties, and Moderate on 45%. The median day sat at AQI 48; one day in ten went above 68.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)70%2,407 days
ozone30%1,044 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	235	128	2	0	42	108
2024	366	242	122	2	0	43	108
2023	365	204	151	10	5	47	265
2022	364	224	138	2	0	46	108
2021	365	197	166	2	0	49	117
2020	170	116	53	1	0	41	115
2019	360	219	137	4	0	46	142
2018	365	206	157	2	0	47	101
2017	365	114	250	1	0	56	127
2016	366	95	264	7	0	55	122
2015	365	174	179	12	0	52	133
2014	365	128	229	8	0	55	121
2013	365	169	185	11	0	52	141
2012	366	114	240	12	0	57	129
2011	306	137	155	14	1	53	151

*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.