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

under 1 bad air day a year

Rare: among the cleanest-air counties EPA monitors. Ranked 796 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (0% particle days).

Which months to watch

Most bad days here fall in June and August. 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 Lawrence

In 2000 to 2009 this county averaged 8 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2022, with 2 bad days on 243 monitored days.

Date	AQI	Main pollutant
2022-06-21	126	Ozone
2023-06-29	119	Ozone
2016-08-27	112	Ozone
2022-06-22	112	Ozone
2022-06-25	100	Ozone

Most days, not the worst ones

Across 2,620 monitored days from 2016 to 2024, the air in Lawrence County rated Good on 94% of them, more often than the 72% typical of monitored counties, and Moderate on 6%. The median day sat at AQI 33; one day in ten went above 47.

The pollutant setting the AQI on an ordinary day here:

ozone100%2,620 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2024	31	31	0	0	0	24	31
2023	267	254	12	1	0	34	119
2022	243	223	18	2	0	37	126
2021	278	259	19	0	0	31	87
2020	363	354	9	0	0	31	93
2019	361	356	5	0	0	31	74
2018	358	329	29	0	0	32	97
2017	364	331	33	0	0	34	90
2016	355	326	28	1	0	33	112
2015	365	332	32	1	0	33	101
2014	365	337	26	2	0	35	119
2013	365	339	23	3	0	34	136
2012	366	306	50	10	1	34	154
2011	365	310	51	4	0	33	129
2010	365	309	53	3	1	33	156

Pennsylvania 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.