Bad Air Days in Washington County, Arkansas: 1 a Year

1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 660 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (18% particle days).

Which months to watch

Most bad days here fall in June 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 worst days on file

In 2000 to 2009 this county averaged under 1 bad days a year; in 2016 to 2025, 1. Not much has changed. The worst recent year was 2023, with 5 bad days on 365 monitored days.

Date	AQI	Main pollutant
2020-06-27	150	PM2.5
2021-06-16	119	Ozone
2022-06-14	119	PM2.5
2023-06-07	119	Ozone
2022-10-15	112	Ozone

An ordinary day in Washington

Across 3,653 monitored days from 2016 to 2025, the air in Washington County rated Good on 66% of them, less often than the 72% typical of monitored counties, and Moderate on 34%. The median day sat at AQI 45; one day in ten went above 60.

The pollutant setting the AQI on an ordinary day here:

ozone52%1,904 days
fine particles (PM2.5)48%1,749 days

Washington County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	304	61	0	0	40	74
2024	366	304	61	1	0	41	101
2023	365	265	95	5	0	44	119
2022	365	214	148	3	0	47	119
2021	365	206	158	1	0	48	119
2020	366	251	114	1	0	44	150
2019	365	193	172	0	0	48	97
2018	365	196	169	0	0	48	87
2017	365	174	191	0	0	51	83
2016	366	311	55	0	0	40	77
2015	365	313	52	0	0	38	90
2014	365	300	65	0	0	41	88
2013	365	258	107	0	0	44	97
2012	366	247	102	17	1	44	151
2011	365	236	124	5	0	45	140
2010	365	255	109	1	0	42	112

*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.