Bad Air Days in Lycoming County, Pennsylvania: under 1 a Year

under 1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 719 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (38% particle days).

The bad-air season here

Most bad days here fall in April and June and May and July and September and December. 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.

Better or worse than it was

In 2000 to 2009 this county averaged 18 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2023, with 3 bad days on 283 monitored days.

Date	AQI	Main pollutant
2024-09-18	122	PM2.5
2023-04-14	119	Ozone
2023-04-21	115	Ozone
2023-06-30	112	Ozone
2021-07-20	111	PM2.5

An ordinary day in Lycoming

Across 3,473 monitored days from 2016 to 2025, the air in Lycoming County rated Good on 82% of them, more often than the 72% typical of monitored counties, and Moderate on 18%. The median day sat at AQI 38; one day in ten went above 54.

The pollutant setting the AQI on an ordinary day here:

ozone69%2,404 days
fine particles (PM2.5)29%1,020 days
coarse dust (PM10)1%49 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Median AQI	Highest AQI
2025*	364	282	81	1	40	105
2024	366	281	84	1	39	122
2023	283	242	38	3	38	119
2022	304	221	83	0	40	80
2021	354	221	132	1	44	111
2020	366	283	82	1	41	109
2019	361	322	39	0	37	77
2018	345	327	18	0	31	97
2017	364	343	21	0	33	84
2016	366	335	30	1	34	108
2015	363	340	23	0	34	87
2014	365	344	21	0	35	93
2013	361	330	31	0	34	97
2012	348	302	42	4	33	108
2011	314	291	22	1	33	101
2010	229	176	47	6	40	119

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

Elsewhere in Pennsylvania

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.